HEADER DESIGN PER 2015 WFCM ENGINEERED and PRESCRIPTIVE PROVISIONS (STD343) John “Buddy” Showalter, P.E

HEADER DESIGN PER 2015 WFCM ENGINEERED AND PRESCRIPTIVE PROVISIONS (STD343) John “Buddy” Showalter, P.E. Vice President, Technology Transfer American Wood Council

Description The 2015 Wood Frame Construction Manual (WFCM) is referenced in the 2015 International Building Code and 2015 International Residential Code. For WFCM load calculations, Minimum Design Loads for Buildings and Other Structures (ASCE 7-10) is used. The 2015 WFCM includes design information for wind and seismic loads and gravity loads including snow, roof live, floor live, and dead loads on buildings up to 3 stories. This presentation will provide background and examples for calculation of forces on headers which will enable designers and code officials to quickly determine design loads. It will also provide engineered prescriptive solutions for both solid sawn and glued-laminated timber headers to resist those loads. Related issues including jack studs, king studs, connections for lateral and gravity loads, and the difference between dropped and raised headers will be discussed.

Learning Objectives Upon completion of this webinar, participants will: 1. Understand applicable lateral and gravity loads from ASCE 7-10 for headers within the WFCM scope. 2. Be familiar with the difference between dropped and raised headers. 3. Be familiar with the design of jack studs and king studs to resist both gravity and lateral loads. 4. Be familiar with the design of lateral, shear, gravity, and uplift connections related to headers.

This presentation is protected by US and International

prohibited.

• The American Wood Council • This course is registered with is a Registered Provider with AIA CES for continuing The American Institute of professional education. As Architects Continuing such, it does not include Education Systems (AIA/CES), content that may be deemed or Provider # 50111237. construed to be an approval or endorsement by the AIA of any • Credit(s) earned on material of construction or any completion of this course will method or manner of be reported to AIA CES for handling, using, distributing, or AIA members. Certificates of dealing in any material or Completion for both AIA product. members and non-AIA members are available upon • Questions related to specific request. materials, methods, and services will be addressed at the conclusion of this presentation.

2 Polling Question 1) What is your profession? a) Architect/Building Designer b) Engineer c) Code Official d) Builder e) Other

3 Course Outline

 Background on Design Loads – Wind and Gravity  Engineered Provisions – Calculating Design Loads  Prescriptive Provisions – Wood Frame Solutions  Design Examples Reference Material

Reference Codes and Standards

 2001 WFCM → 2003, 2006, 2009 IRC/IBC  2012 WFCM → 2012 IRC/IBC  2015 WFCM → 2015 IRC/IBC

 ASCE 7-10 → 2015 WFCM

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WFCM Wood Frame Construction Manual for One- and Two-Family Dwellings COMMENTARY 2015 EDITION

6 GENERAL INFORMATION

C1.1 Scope

C1.1.1 General no significant structural discontinuities. In addition, the buildings are assumed to be enclosed structures in which The scope statement limits applicability of the provi- the structural elements are protected from the weather. sions of the Wood Frame Construction Manual to one- and Partially enclosed structures are subjected to loads that two-family dwellings. This limitation is related primarily require further consideration. to assumed design loads and to structural configurations. For wind load calculations, ASCE 7-10 is used. ASCE Code prescribed floor design loads for dwellings gener- 7-10 calculations are based on 700-year return period ally fall into the range of 30 to 40 psf, with few additional “three second gust” wind speeds corresponding to an ap- requirements such as concentrated load provisions. In proximate 7% probability of exceedence in 50 years, and these applications, use of closely spaced framing members use combined gust and pressure coefficients to translate covered by structural sheathing has proven to provide a these wind speeds into peak design pressures on the struc- reliable structural system. ture. The 2015 WFCM includes design information for buildings located in regions with 700-year return period C1.1.2 Design Loads “three second gust” design wind speeds between 110 and 195 mph. Unless stated otherwise, all calculations are based Basic Design Equations: on standard linear elastic analysis and Allowable Stress ASD wind pressures, pmax, for Main Wind-Force Re- Design (ASD) load combinations using loads from ASCE sisting Systems (MWFRS) and Components and Cladding 7-10 Minimum Design Loads for Buildings and Other (C&C) are computed by the following equations, taken Structures. from ASCE 7-10: Dead Loads Unless stated otherwise, tabulated values assume the MWFRS – Envelope Procedure: following dead loads: p = q[(GC ) – (GC )] (lbs/ft2) Roof 10 psf max pf pi Ceiling 5 psf where: Floor 10 psf q = 0.60 qh 12 psf (for Seismic) 2 Walls 11 psf qh = 0.00256KzKztKdV (ASCE 7-10 Partitions 8 psf (for Seismic) Equation 28.3-1)

Live Loads GCpf = external pressure coefficients (ASCE 7-10 Unless stated otherwise, tabulated values assume the Figure 28.4-1) following live loads: GCpi = internal pressure coefficients (ASCE 7-10 Roof 20 psf Table 26.11-1) Floor (sleeping areas) 30 psf Floor (living areas) 40 psf C&C: 2 pmax = q[(GCp) – (GCpi)] (lbs/ft ) Wind Loads where: Wind forces are calculated assuming a “box-like” structure with wind loads acting perpendicular to wall q = 0.60qh and roof surfaces. Lateral loads flow into roof and floor 2 qh = 0.00256KzKztKdV (ASCE 7-10 diaphragms and are transferred to the foundation via shear Equation 30.3-1) walls. Roof uplift forces are transferred to the foundation by direct tension through the wall framing and tension GCp = external pressure coefficients (ASCE7-10 straps or wall sheathing. Shear wall overturning forces are Figures 30.4-1,30.4-2A, B, &C) resisted by the structure’s dead load and by supplemental GCpi = internal pressure coefficients (ASCE 7-10 hold down connections. Table 26.11-1) Implicit in the assumption of a “box-like” structure is a roughly rectangular shape, relatively uniform distri- The calculation of ASD velocity pressure, q, for various bution of shear resistance throughout the structure, and wind speeds and Exposures is shown in Table C1.1.

Table C1.1 ASD Velocity Pressure, q (psf), for Exposures B, C, and D and 33' MRH 1 Exposure ASD Velocity Pressure, q GENERAL INFORMATION Category (psf) 700-yr. Wind Speed 3-second gust (mph) 110 115 120 130 140 150 160 170 180 195 Exposure B 11.37 12.43 13.54 15.89 18.42 21.15 24.06 27.17 30.46 35.74 Exposure C 15.80 17.27 18.80 22.06 25.59 29.38 33.42 37.73 42.30 49.65 Exposure D 18.64 20.37 22.18 26.04 30.20 34.66 39.44 44.52 49.92 58.58

q = 0.6 qh

2 qh = 0.00256 Kz Kzt Kd V and

Kz (33 ft) = 0.72 ASCE 7-10 Table 28.3-1 (MWFRS), Table 30.3-1(C&C) at mean roof height (MRH) of 33 ft

Kzt = 1.0 No topographic effects

Kd = 0.85 ASCE 7-10 Table 26.6-1 Design wind pressures in ASCE 7-10 are based on an intermediate floor diaphragms (one-half from above and ultimate 700-year return period. Since the WFCM uses al- one-half from below) and one-half of the bottom story lowable stress design, forces calculated from design wind goes directly into the foundation. pressures are multiplied by 0.60 in accordance with load Lateral roof and wall pressures for determining combination factors per ASCE 7-10. diaphragm and shear wall loads are calculated using en- For example, the ASD velocity pressure, q, at 150 mph veloped MWFRS coefficients. Spatially-averaged C&C for Exposure B is calculated as follows: coefficients are used for determining lateral framing loads, suction pressures on wall and roof sheathing, and exterior q = 0.6 (0.00256)(0.72)(1.0)(0.85)(150)2 (lbs/ft2) stud capacities. 2 = 21.15 (lbs/ft ) Uplift Calculations Uplift for roof cladding is calculated using C&C loads. Note that the worst case of internal pressurization Uplift connections for roof framing members are calculat- is used in design. Internal pressure and internal suction ed using enveloped MWFRS loads. The rationale for using for MWFRS are outlined in WFCM Tables C1.3A and MWFRS loads for computing the uplift of roof assemblies C1.3B, respectively. Pressure coefficients and loads for recognizes that the spatial and temporal pressure fluctua- wind parallel and perpendicular to ridge are tabulated. tions that cause the higher coefficients for components Parallel to ridge coefficients are used to calculate wind and cladding are effectively averaged by wind effects on loads acting perpendicular to end walls. Perpendicular-to- different roof surfaces. The uplift load minus sixty percent ridge coefficients are used to calculate wind loads acting of the roof and/or ceiling dead load is applied at the top perpendicular to side walls. of the uppermost wall. As this load is carried down the Pressures resulting in shear, uplift, and overturning wall, the wall dead load is included in the analysis. The forces are applied to the building as follows: dead load from floors framing into walls is not included, Shear Calculations in order to eliminate the need for special framing details The horizontal component of roof pressures is applied where floors do not directly frame into walls. as a lateral load at the highest ceiling level (top of the up- Overturning Calculations permost wall). Overturning of the structure as a result of lateral loads Windward and leeward wall pressures are summed is resisted at the ends of shear walls in accordance with and applied (on a tributary area basis) as lateral loads at general engineering practice, typically with hold downs or each horizontal diaphragm. For example, in typical two other framing anchorage systems. In the WFCM, overturn- story construction, one-half of the height of the top wall ing loads are differentiated from uplift loads. Overturning goes to the roof or ceiling level, a full story height goes to moments result from lateral loads which are resisted by

shear walls. Uplift forces arise solely from uplift on the b. Building Length and Width Limiting the maxi- roof, and are transferred directly into the walls supporting mum building length and width to 80 feet is provided as a the roof framing. reasonable upper limit for purposes of tabulating require- ASCE 7-10 requires checking the MWFRS with a ments in the WFCM. minimum 5 psf ASD lateral load on the vertical projected C1.1.3.2 Floor, Wall, and Roof Systems area of the roof and a 10 psf ASD lateral load on the wall. See C2.1.3.2 (Floor Systems), C2.1.3.3 (Wall Sys- The 2015 WFCM incorporates this design check. tems), and C2.1.3.4 (Roof Systems). Snow Loads The 2015 WFCM includes design information for C1.1.4 Foundation Provisions snow loads in accordance with ASCE 7-10 for buildings located in regions with ground snow loads between 0 and Design of foundations and foundation systems is 70 psf. Both balanced and unbalanced snow load condi- outside the scope of this document. tions are considered in design. Seismic Loads C1.1.5 Protection of Openings The 2015 WFCM includes seismic design information in accordance with ASCE 7-10 for buildings located in Wind pressure calculations in the WFCM assume that Seismic Design Categories A-D, as defined by the 2015 buildings are fully enclosed and that the building envelope IRC. is not breached. Interior pressure coefficients, GCpi, of +/-0.18 are used in the calculations per ASCE 7-10 Table C1.1.2.1 Torsion 26.11-1. Penetration of openings (e.g. windows and doors) Design for torsion is outside the scope of this docu- due to flying debris can occur in sites subject to high winds ment. with a significant debris field. Where these areas occur, C1.1.2.2 Sliding Snow opening protection or special glazing requirements may be Design for sliding snow is outside the scope of this required by the local authority to ensure that the building document. envelope is maintained.

C1.1.3 Applicability C1.1.6 Ancillary Structures

C1.1.3.1 Building Dimensions Design of ancillary structures is outside the scope of a. Mean Roof Height Building height restrictions this document. limit the wind forces on the structure, and also provide as- surance that the structure remains “low-rise” in the context of wind and seismic-related code requirements. The tables in the WFCM are based on wind calculations assuming a 33 ft mean roof height, (MRH). This assumption permits table coverage up to a typical 3-story building. Footnotes have been provided to adjust tabulated requirements to lesser mean roof heights.

Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized. AMERICAN WOOD COUNCIL 9 Polling Question 2) The 0.6 adjustment to wind pressures in WFCM is based on which of the following? a) Topographic effects b) ASCE 7-10 load combinations c) Converting ultimate to allowable stress design d) All of the above e) b) and c)

10 By downloading this file to your computer, you are accepting and agreeing to the terms of AWC’s end-user license agreement (EULA), which may be viewed here: End User License Agreement. Copyright infringement is a violation of federal law subject to criminal and civil penalties.

WFCM Wood Frame Construction Manual for One- and Two-Family Dwellings 2015 EDITION

ANSI/AWC WFCM-2015 Approval date October 10, 2014 11 GENERAL INFORMATION

Table 1 Applicability Limitations

Reference Attribute Limitation Section Figures

BUILDINGDIMENSIONS

MeanRoofHeight(MRH) 33' 1.1.3.1a 1.2 NumberofStories 3 1.1.3.1a Ͳ BuildingLengthandWidth 80' 1.1.3.1b Ͳ LOADASSUMPTIONS (SeeChapter2orChapter3tablesforloadassumptions applicabletothespecifictabulatedrequirement) LoadType LoadAssumption PartitionDeadLoad 0Ͳ8psfoffloorarea WallAssemblyDeadLoad 11Ͳ18psf FloorDeadLoad 10Ͳ20psf Roof/CeilingAssemblyDeadLoad 0Ͳ25psf FloorLiveLoad 30Ͳ40psf RoofLiveLoad 20psf CeilingLiveLoad 10Ͳ20psf GroundSnowLoad 0Ͳ70psf 110Ͳ195mphwindspeed WindLoad (700Ͳyr.returnperiod,3Ͳsecondgust) ExposureB,C,andD SeismicDesignCategory(SDC) SeismicLoad SDCA,B,C,D0,D1,andD2

AMERICAN WOOD COUNCIL 12 WOOD FRAME CONSTRUCTION MANUAL

ENGINEERED 2 DESIGN

2.1 General Provisions 15 2.2 Connections 17 2.3 Floor Systems 19 2.4 Wall Systems 21 2.5 Roof Systems 23 List of Figures 26 List of Tables 61

Table 2 Engineered Design Limitations Reference Attribute Limitation Section Figures BUILDING DIMENSIONS Building Mean Roof Height (MRH) 33' 2.1.3.1 1.2 Number of Stories 3 1.1.3.1a ‐ Building Length and Width 80' 1.1.3.1b ‐ FLOOR SYSTEMS Lumber Joists Joist Span 26' 2.1.3.2a ‐ Joist Spacing 24" o.c. 2.1.3.2b ‐ Cantilevers ‐ Supporting loadbearing d 2.1.3.2c 2.1a Setbacks ‐ Loadbearing walls1 d 2.1.3.2d 2.1d Wood I‐Joists I‐Joist Span 26' 2.1.3.2a ‐ I‐Joist Spacing 24" o.c. 2.1.3.2b ‐ Cantilevers (see manufacturer) 2.3.2.6 2.4e, 2.9a, 2.9b Setbacks (see manufacturer) 2.3.2.5 2.4d Wood Floor Trusses Truss Span 26' 2.1.3.2a ‐ Truss Spacing 24" o.c. 2.1.3.2b ‐ Cantilevers (see truss plans) 2.3.3.6 2.13a, 2.13b Setbacks (see truss plans) 2.3.3.5 ‐ 1 Floor Diaphragms Vertical Floor Offset df 2.1.3.2e 2.1i Floor Diaphragm Aspect Ratio1 4:1 2.1.3.2f 2.1j Floor Diaphragm Openings Lesser of 12' or 50% of Building 2.1.3.2g 2.1k Dimension WALL SYSTEMS Wall Studs Loadbearing Wall Height 20' 2.1.3.3a ‐ Non‐Loadbearing Wall Height 20' 2.1.3.3a ‐ Wall Stud Spacing 24" o.c. 2.1.3.3b ‐ Shear Walls Shear Wall Line Offset1 4' 2.1.3.3c 2.1l Shear Wall Story Offset1 No offset unless per Exception 2.1.3.3d Shear Wall Segment Aspect Ratio (see SDPWS ) 2.1.3.3e ROOF SYSTEMS Lumber Rafters Rafter Span (Horizontal Projection)2 26' 2.1.3.4a ‐ Rafter Spacing 24" o.c. 2.1.3.4b ‐ Eave Overhang Length1 Lesser of 2' or rafter span/3 2.5.1.1.2 2.1f Roof Slope Flat ‐ 12:12 2.1.3.4d ‐ Wood I‐Joist Roof I‐Joist Span 26' 2.1.3.4a ‐ System I‐Joist Spacing 24" o.c. 2.1.3.4b ‐ Eave Overhang Length (see manufacturer) 2.5.2.1.2 ‐ Roof Slope Flat ‐ 12:12 2.1.3.4d ‐ Wood Roof Trusses Truss Span 60' 2.1.3.4a ‐ Truss Spacing 24" o.c. 2.1.3.4b ‐ Eave Overhang Length (see truss plans) 2.5.3.1 ‐ Roof Slope Flat ‐ 12:12 2.1.3.4d ‐ Rakes Overhang Length1 Lesser of 2' or purlin span/3 2.1.3.4c 2.1g Roof Diaphragms Roof Diaphragm Aspect Ratio1 4:1 2.1.3.4e 2.1j 1 See exceptions. 2 For roof snow loads, tabulated spans are limited to 20 ft. Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized. AMERICAN WOOD COUNCIL 14 WOOD FRAME CONSTRUCTION MANUAL

2.1 General Provisions

2.1.1 Engineered Requirements Table 2.1.3.1 Adjustment for Wind Exposure 2 The provisions of this Chapter provide minimum loads and Mean Roof Height for the purpose of establishing specific resistance require-

ments for buildings within the scope of this document. This Mean Roof ENGINEERED DESIGN Chapter includes the results of engineering calculations Height Exposure Exposure Exposure for specific structural elements, in specific configurations, (feet) B C D under specific loads. The tabulated information does not 0-15 1.00 1.18 1.43 represent a complete engineering analysis as would be 20 1.00 1.25 1.50 performed by a registered professional engineer, but is 25 1.00 1.31 1.56 expected to result in significant time-savings for the design professional. 30 1.00 1.36 1.61 33 1.00 1.39 1.64 2.1.2 Continuous Load Path b. Framing Member Spacings Floor framing member A continuous load path shall be provided to transfer spacings shall not exceed 24 inches on center for lumber all lateral and vertical loads from the roof, wall, and floor joists, I-joists, and floor trusses. systems to the foundation. c. Cantilevers Lumber floor joist cantilevers sup- 2.1.3 Engineered Design Limitations porting loadbearing walls shall not exceed the depth, d, of the joists (see Figure 2.1a). Lumber floor joist cantilevers Wood-frame buildings built in accordance with this supporting non-loadbearing walls shall be limited to L/4 document shall be limited to the conditions of this section (see Figure 2.1b). I-joist cantilevers shall be in accordance (see Table 2). Structural conditions not complying with with the manufacturer’s code evaluation report. Truss this section shall be designed in accordance with accepted cantilevers shall be in accordance with the truss design/ engineering practice. placement plans. Lumber joists, I-joists, and trusses shall be located directly over studs when used in cantilever 2.1.3.1 Adjustment for Wind Exposure and conditions, unless the top plate is designed to carry the Mean Roof Height load. Tabulated wind requirements in this chapter are based on wind exposure category B and a mean roof height of 33 EXCEPTION: Lumber floor joist cantilevers feet. The building shall neither exceed three stories nor a supporting loadbearing walls shall be permit- mean roof height of 33 feet, measured from average grade ted to exceed these limits when designed for the to average roof elevation (see Figure 1.2). Additional loads additional loading requirements, but in no case from habitable attics shall be considered for purposes of shall they exceed four times the depth (4d) of the determining gravity and seismic loads. For buildings sited member (see Figure 2.1c). in exposure category C or D, wind-related tabulated values shall be increased in accordance with specific adjustments d. Setbacks Setbacks of loadbearing walls on lumber as provided in table footnotes or per Table 2.1.3.1. floor joist systems shall not exceed the depth, d, of the joists (see Figure 2.1d). Setbacks on I-joists shall be in 2.1.3.2 Floor Systems accordance with the manufacturer’s code evaluation report. a. Framing Member Spans Single spans of floor Setbacks on floor trusses shall be in accordance with the framing members shall not exceed 26 feet for lumber joists, truss design/placement plans. Lumber joists, I-joists, and I-joists, and floor trusses. Design spans shall consider both trusses shall be located directly over studs when used in strength and serviceability limits. For serviceability, the setback conditions supporting loadbearing walls, unless computed joist deflection under live load shall not exceed the top plate is designed to carry the load. L/360 (span divided by 360) or more stringent criteria as specified by the manufacturer. EXCEPTION: Lumber floor joist setbacks supporting loadbearing walls shall be permit-

2.1.5.4 Floor and Roof Diaphragm Assemblies 2.1.5.5 Wall Assemblies Design of horizontal diaphragm assemblies shall be Design of vertical wall assemblies shall be in accor- in accordance with the SDPWS. dance with the NDS and SDPWS. a. Maximum spans and allowable total uniform loads a. ASD allowable uniform load capacities for wall for floor sheathing are specified in Table S-1 of theWFCM sheathing resisting out-of-plane wind loads shall be deter- 2 Supplement. mined from SDPWS Section 3.2.1 by dividing the tabulated b. Allowable stress design (ASD) allowable uniform nominal uniform load capacities in Table 3.2.1 of SDPWS load capacities for wind design shall be determined from by an ASD reduction factor of 1.6, modified by applicable ENGINEERED DESIGN SDPWS Section 3.2.3 for roof sheathing by dividing the footnotes in SDPWS. tabulated nominal uniform load capacities in Table 3.2.2 b. ASD allowable unit shear capacities for shear wall of SDPWS by an ASD reduction factor of 1.6, modified assemblies are determined from SDPWS Section 4.3 by by applicable footnotes in SDPWS. Maximum spans and dividing the tabulated nominal unit shear capacities in allowable total uniform loads for roof live and snow loads Tables 4.3A, B, and C of SDPWS by an ASD reduction for roof sheathing are specified in Table S-2 of theWFCM factor of 2.0, modified by applicable footnotes inSDPWS . Supplement. c. ASD allowable unit shear capacities for horizontal 2.1.5.6 Fasteners diaphragm assemblies are determined from SDPWS Section Design of fasteners shall be in accordance with the 4.2 by dividing the tabulated nominal unit shear capacities NDS. Reference lateral design values for common, box, in Tables 4.2A, B, and C of SDPWS by an ASD reduction or sinker steel wire nails are specified in the NDS Tables factor of 2.0, modified by applicable footnotes inSDPWS . 11N, P, Q, and R. Reference withdrawal values for nails d. For horizontal diaphragm assemblies sheathed are specified in theNDS Table 11.2C. with gypsum wallboard, the allowable unit shear capacity is specified inWFCM Supplement Table S-3.

2.2 Connections

2.2.1 Lateral Framing Connections 2.2.2.1 Roof, Ceiling, or Floor Assembly to Wall Assembly Adequate connections between roof, ceiling, wall, and Connections to transfer shear loads from the roof, floor assemblies shall be provided to transfer lateral forces ceiling, or floor diaphragm assembly to the shear wall acting perpendicular to the wall surface (see Figure 2.2a). segments shall be in accordance with the shear loads calculated using Tables 2.5A and 2.5B for wind perpendicular 2.2.1.1 Wall Assembly to Roof, Ceiling, or Floor and parallel to ridge respectively, or using Table 2.6 for Assembly seismic motion. Framing connections to transfer lateral loads from the wall framing into the roof, ceiling, or floor diaphragm 2.2.2.2 Wall Assembly to Wall Assembly assembly shall be in accordance with the lateral loads Connections to transfer shear loads from a shear wall specified in Table 2.1. segment above to a shear wall segment below shall be in accordance with the shear loads calculated using Tables 2.2.1.2 Foundation Wall to Floor Assembly 2.5A and 2.5B for wind perpendicular and parallel to ridge respectively, or using Table 2.6 for seismic motion. Framing connections to transfer lateral loads from the foundation wall into the floor diaphragm assembly shall 2.2.2.3 Floor Assembly to Foundation be in accordance with the foundation design. Connections to transfer shear loads from the floor assembly to the foundation shall be in accordance with the 2.2.2 Shear Connections shear loads using Tables 2.5A and 2.5B for wind perpendicular and parallel to ridge respectively, or using Table Adequate connections between roof, ceiling, wall, and 2.6 for seismic motion. floor assemblies shall be provided to transfer shear forces acting parallel to the wall surface (see Figure 2.2b). 2.2.2.4 Wall Assembly to Foundation Connections to transfer shear loads from the wall assembly to the foundation shall be in accordance with the Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized. AMERICAN WOOD COUNCIL 16 ENGINEERED DESIGN

shear loads calculated using Tables 2.5A and 2.5B for wind in 2.4.4.2. perpendicular and parallel to ridge respectively, or using Table 2.6 for seismic motion. 2.2.5.3 Floor Sheathing Sheathing shall be attached to provide the floor dia- 2.2.3 Wind Uplift Connections phragm shear capacity required in 2.3.4.2.

Adequate connections shall be provided to transfer 2.2.6 Special Connections uplift forces acting away from the roof surface(s) (see Figure 2.2c). 2.2.6.1 Ridge Connections Connection loads at the roof ridge shall be in accor- 2.2.3.1 Roof Assembly to Foundation dance with the loads specified in Table 2.2B. Connections to transfer uplift loads from the roof assembly to the foundation shall be in accordance with the 2.2.6.2 Jack Rafters uplift loads specified in Table 2.2A. A continuous load Connection of the jack rafter to the wall shall be in path shall be maintained with either a continuous con- accordance with 2.2.3.1. Connection of the jack rafter to nector from the roof to the foundation or with a series of hip beam shall be in accordance with the loads specified connections creating a complete load path. in Table 2.2B. 2.2.6.3 Hip and Valley Beams 2.2.4 Overturning Resistance Hip and valley beams do not require special uplift Resistance to shear wall overturning shall be provided connections when jack rafters are attached in accordance (see Figure 2.2d). The resisting dead load moment shall be with 2.2.6.2. calculated using no more than 60% of the design dead load. 2.2.6.4 Hip Trusses 2.2.4.1 Hold-downs Gravity and uplift loads at the hip truss to girder truss Hold-downs to provide overturning restraint to shear connection shall be in accordance with the loads specified wall segments at each level shall be provided at the ends of in the truss design drawings. shear walls and as required to develop the shear capacity of 2.2.6.5 Non-Loadbearing Exterior Wall the wall segments in accordance with 2.4.4.2. A continu- Assemblies ous load path from the hold-down to the foundation shall Walls which support rake overhang outlookers or be maintained. Where a hold-down resists the overturning lookout blocks shall be connected to the foundation in load from the story or stories above, the hold-down shall accordance with the uplift loads specified in Table 2.2C be sized for the required hold-down tension capacity at (see Figure 2.1g and 2.1h). Walls which do not support its level plus the required hold-down tension capacity of the roof assembly need only resist an uplift load of 60 plf. the story or stories above. Hold-downs used to resist both uplift and overturning shall be designed to resist the sum of 2.2.6.6 Wall Openings the forces determined in accordance with 2.2.3 and 2.2.4. Connections to transfer lateral, shear, and uplift loads around wall openings shall be in accordance with the loads 2.2.5 Sheathing and Cladding Attachment specified in 2.2.1.1, 2.2.2, and 2.2.3.1 for loadbearing walls or 2.2.1.1, 2.2.2, and 2.2.6.5 for non-loadbearing walls. Adequate attachment of sheathing and cladding shall A continuous load path shall be maintained around the be provided to assure the transfer of specified loads into opening and to the foundation. framing members. 2.2.6.7 Thrust Connection 2.2.5.1 Roof Sheathing Connection to transfer thrust loads in the lower third Roof sheathing shall be attached to roof structural of the attic space shall be in accordance with the thrust members to resist the withdrawal loads (suction) specified loads specified in Table 2.3. in Table 2.4 and provide the roof diaphragm shear capacity required in 2.5.4.2. 2.2.6.8 Rake Overhang Outlookers Rake overhang outlookers shall be connected to the 2.2.5.2 Wall Sheathing gable endwall in accordance with the uplift loads specified Wall sheathing shall be attached to wall structural in Table 2.2C (see Figure 2.1g). members to resist the withdrawal loads (suction) specified in Table 2.4 and provide the shear wall capacity required Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized. AMERICAN WOOD COUNCIL 17 Lateral, Shear, and Uplift Loads

18 WOOD FRAME CONSTRUCTION MANUAL

2.3.3.3 End Restraint the floor framing members. Sheathing shall be continuous Restraint against twisting shall be provided at the over two or more spans. end of each truss by fastening to a full-height rim, band joist, header, or other member or by using blocking panels 2.3.4.2 Shear Capacity between truss ends. Framing details (see Figure 2.15a) Floor sheathing and fasteners shall be capable of re- 2 for end restraint shall be provided in a manner consistent sisting the total shear loads calculated using Tables 2.5A with SBCA/TPI’s Building Component Safety Information and 2.5B for wind perpendicular and parallel to ridge

(BCSI) – Guide to Good Practice for Handling, Installing, respectively, or using Table 2.6 for seismic motion. ENGINEERED DESIGN Restraining, & Bracing of Metal Plate Connected Wood 2.3.4.2.1 Diaphragm Chords Diaphragm chords Trusses, or ANSI/TPI 1, or 2.3.3.1. shall be continuous for the full length of the diaphragm. Diaphragm members and chord splices shall be capable 2.3.3.4 Chord and Web Bracing of resisting the chord forces, calculated by the following Chord and web bracing shall be provided in a manner equation: consistent with the guidelines provided in BCSI, ANSI/TPI vL 1, or in accordance with 2.3.3.1, and the bracing require- T = (2.3-1) ments specified in the construction design documents (see 4 Figure 2.14). where: T = Chord force, lbs 2.3.3.5 Single or Continuous Floor Trusses v = Required unit shear capacity of the floor Supporting Walls diaphragm, plf Floor trusses shall be designed for any intermediate L = Floor diaphragm dimension perpendicular to the loads and supports as shown on the construction docu- lateral load, ft ments and/or plans. 2.3.4.3 Sheathing Edge Support 2.3.3.6 Cantilevered Trusses Edges of floor sheathing shall have approved tongue- Cantilevered floor trusses shall be designed for all and-groove joints or shall be supported with blocking, anticipated loading conditions (see Figures 2.13a-b). unless 1/4-inch minimum thickness underlayment or 1-1/2 inches of approved cellular or lightweight concrete is in- 2.3.3.7 Floor Openings stalled, or unless the finish floor is of 3/4-inch wood strip. Framing around floor openings shall be designed to transfer loads to adjacent framing members that are 2.3.5 Floor Diaphragm Bracing designed to support the additional concentrated loads. Fasteners, connections, and stiffeners shall be designed At panel edges perpendicular to floor framing mem- for the loading conditions. bers, framing and connections shall be provided to transfer the lateral wind loads from the exterior wall to the floor 2.3.4 Floor Sheathing diaphragm assembly in accordance with the requirements of Table 2.1 (see Figure 2.3). 2.3.4.1 Sheathing Spans Floors shall be fully sheathed with sheathing capable of resisting and transferring the applied gravity loads to

2.4 Wall Systems

2.4.1 Exterior Walls 2.11 for the gravity loads specified. Exterior loadbearing studs shall be designed to resist the uplift loads specified 2.4.1.1 Wood Studs in Table 2.2A, independent of the requirements of Tables Exterior wall studs shall be in accordance with the 2.9A, 2.9B, 2.10, and 2.11. Exterior non-loadbearing studs requirements of Table 2.9A or Table 2.10 for the wind shall be designed to resist the rake overhang uplift loads loads specified. Exterior loadbearing studs shall be in specified in Table 2.2C. accordance with the requirements of Table 2.9B or Table 2.4.1.1.1 Notching and Boring Notches in either edge Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized. AMERICAN WOOD COUNCIL 19 ENGINEERED DESIGN

of studs shall not be located in the middle one-third of the with the lateral capacity requirements of able 2.1 and the stud length. Notches in the outer thirds of the stud length graity capacity requirements of able 2.11. shall not exceed 25% of the actual stud depth. Bored holes 2.4.1.4.2 Studs Supporting Header Beams Wall and shall not exceed 40% of the actual stud depth and the edge jack studs shall be in accordance with the same require- of the hole shall not be closer than 5/8-inch to the edge ments as exterior wall studs selected in 2.4.1.1. Wall and of the stud. Notches and holes shall not occur in the same jack studs shall be designed for additional lateral and uplift cross-section (see Figure 3.3b). loads from headers and window sill plates in accordance with able 2.1 and able 2.2A. EXCEPTION: Bored holes shall not exceed 60% 2.4.1.4.3 Window Sill Plates Window sill plates shall of the actual stud depth when studs are doubled. be in accordance with the lateral capacity requirements of able 2.1. 2.4.1.1.2 Stud Continuity Studs shall be continuous between horizontal supports, including but not limited to: 2.4.2 Interior Loadbearing Partitions girders, oor diaphragm assemblies, ceiling diaphragm assemblies, and roof diaphragm assemblies. Where attic 2.4.2.1 Wood Studs oor diaphragm or ceiling diaphragm assemblies are used Interior loadbearing studs shall be in accordance with to brace gable endwalls, the sheathing and fasteners shall the requirements of able 2.9C or able 2.11 for graity be capable of resisting the minimum shear requirements loads. of able 2.5C. 2.4.2.1.1 Notching and Boring Notches in either edge 2.4.1.1.3 Corners Corner framing shall be capable of of studs shall not be located in the middle one-third of the transferring axial tension and compression loads from the stud length. Notches in the outer thirds of the stud length shear walls and the structure aboe, connecting adjoining shall not exceed 25% of the actual stud depth. Bored holes walls, and proiding adequate backing for the attachment in interior loadbearing studs shall not exceed 40% of the of sheathing and cladding materials. actual stud depth and shall not be closer than 5/8-inch to the edge. Notches and holes shall not occur in the same 2.4.1.2 Top Plates cross-section (see Figure 3.3b). Exterior stud walls shall be capped with a single or double top plate with bearing capacity in accordance with EXCEPTION: Bored holes shall not exceed 60% able 2.9B, and bending capacity in accordance with able of the actual stud depth when studs are doubled. 2.11. op plates shall be tied at joints, corners, and intersecting walls to resist and transfer lateral loads to the roof 2.4.2.1.2 Stud Continuity Studs shall be continuous or oor diaphragm in accordance with the requirements between horizontal supports, including but not limited to: of able 2.1. Double top plates shall be lap spliced and girders, oor diaphragm assemblies, ceiling diaphragm oerlap at corners and intersections with other exterior and assemblies, and roof diaphragm assemblies. interior loadbearing walls. 2.4.2.2 Top Plates 2.4.1.3 Bottom Plate Interior loadbearing partition walls shall be capped Wall studs shall bear on a bottom plate with bearing with a single or double top plate with bearing capacity in capacity in accordance with able 2.9B. he bottom plate accordance with able 2.9C, and bending capacity in ac- shall not be less than 2 inch nominal thickness and not less cordance with able 2.11. op plates shall be tied at joints, than the width of the wall studs. Studs shall hae full bear- corners, and intersecting walls. Double top plates shall be ing on the bottom plate. Bottom plates shall be connected to lap spliced and oerlap at corners and at intersections with transfer lateral loads to the oor diaphragm or foundation other exterior and interior loadbearing walls. in accordance with the requirements of able 2.1. Bottom plates that are connected directly to the foundation shall 2.4.2.3 Bottom Plate hae full bearing on the foundation. Wall studs shall bear on a bottom plate with bearing capacity in accordance with able 2.9C. he bottom plate 2.4.1.4 Wall Openings shall not be less than 2 inch nominal thickness and not Headers shall be proided oer all exterior wall open- less than the width of the wall studs. Studs shall hae full ings. Headers shall be supported by wall studs, jack studs, bearing on the bottom plate. hangers, or framing anchors. 2.4.1.4.1 Headers Headers shall be in accordance

AMERICAN WOOD COUNCIL 20 WOOD FRAME CONSTRUCTION MANUAL

2.4.2.4 Wall Openings 2.4.4 Wall Sheathing Headers shall be proided oer all interior loadbearing wall openings. Headers shall be supported by wall studs, 2.4.4.1 Sheathing Spans jack studs, hangers, or framing anchors. Exterior wall sheathing shall be capable of resisting 2.4.2.4.1 Headers Headers shall be in accordance with and transferring the wind suction loads specied in able 2 the load requirements of able 2.11. 2.4 to the wall framing. 2.4.2.4.2 Studs Supporting Header Beams Wall and jack studs shall be in accordance with the same require- 2.4.4.2 Shear Walls ENGINEERED DESIGN ments as interior loadbearing wall studs selected in 2.4.2.1. Walls parallel to the applicable wind load or seismic motion shall proide the required shear resistance at each 2.4.3 Interior Non-Loadbearing Partitions leel. he sum of the indiidual shear wall segment shear capacities shall meet or exceed the sum of shear loads 2.4.3.1 Wood Studs collected by horizontal diaphragms aboe. otal shear Interior non-loadbearing studs shall be of adequate loads shall be calculated using ables 2.5A and 2.5B for size and spacing to carry the weight of the applied nish. wind perpendicular and parallel to ridge respectiely, or 2.4.3.1.1 Notching and Boring Notches in studs shall using able 2.6 for seismic motion. Design loads shall be not exceed 40% of the actual stud depth. Bored holes shall distributed to the arious ertical elements of the seismic not exceed 60% of the actual stud depth and shall not be force-resisting system in the story under consideration, closer than 5/8-inch to the edge. Notches and holes shall based on the relatie lateral stiffness of the ertical resist- not occur in the same cross-section. ing elements and the diaphragm.

2.4.3.2 Top Plates 2.4.4.3 Sheathing Edge Support All interior non-loadbearing partitions shall be capped All shear wall sheathing edges shall be supported. with single or double top plates.

2.4.3.3 Bottom Plate Wall studs shall bear on at least one bottom plate.

2.5 Roof Systems

2.5.1 Wood Rafter Systems 2.5.1.1.4 Notching and Boring Notches in the top or bottom edge of rafters shall not be located in the middle 2.5.1.1 Rafters one-third of the rafter span. Notches in the outer thirds Rafters shall be in accordance with the maximum of the span shall not exceed one-sixth of the actual rafter spans (horizontal projection) as specied in ables 2.14A- depth. Where notches are made at the supports, they shall D. he span of each rafter shall be measured along the not exceed one-fourth the actual rafter depth. Bored holes horizontal projection of the rafter. are limited in diameter to one-third the actual rafter depth 2.5.1.1.1 Jack Rafters Jack rafters shall be in accor- and the edge of the hole shall not be closer than 2 inches dance with 2.5.1.1. to the top or bottom edge of the rafter (see Figure 3.3a). 2.5.1.1.2 Rafter Overhangs Rafter oerhangs shall not exceed the lesser of one-third of the rafter span or 2 2.5.1.2 Bearing feet (see Figure 2.1f). Rafters shall bear directly on beams, girders, ledgers, 2.5.1.1.3 Rake Overhangs Rake oerhang outlookers or loadbearing walls or be supported by hangers or fram- shall use continuous 2x4 purlins connected in accordance ing anchors. with 2.2.6.8. Rake oerhangs shall not exceed the lesser of one-half of the purlin length or 2 feet (see Figure 2.1g). 2.5.1.3 End Restraint Where the nominal depth-to-thickness ratio of a rafter EXCEPTION: Rake oerhangs using lookout exceeds 3, restraint against twisting shall be proided at blocks shall not exceed 1 foot (see Figure 2.1h). the end of each rafter by fastening to a rim board or by

AMERICAN WOOD COUNCIL 21 Polling Question 3) Load-bearing wall header connections are designed for which of the following loads? a) Lateral b) Shear c) Uplift d) All of the above e) a) and c) only

22 WOOD FRAME CONSTRUCTION MANUAL

List of Tables

2.1 Lateral Framing Connection Loads from 2.10 Exterior Wall Induced Moments from Wind...... 62 Wind Loads...... 85 2 2.2A Uplift Connection Loads from Wind...... 63 2.11 Loadbearing Wall Loads from Snow or Live Loads...... 86 2.2B Ridge Connection Loads from Wind...... 64 ENGINEERED DESIGN 2.12A1-2 Ceiling Joist Spans for 10 psf Live Load..... 87 2.2C Rake Overhang Outlooker Uplift Connection Loads...... 65 2.12B1-2 Ceiling Joist Spans for 20 psf Live Load..... 89 2.3 Thrust Connection Loads...... 66 2.13A1-2 Ceiling Joist Framing Capacity Requirements (without storage)...... 91 2.4 Roof and Wall Sheathing Suction Loads...... 67 2.13B1-2 Ceiling Joist Framing Capacity 2.5A Lateral Diaphragm Loads from Wind - Requirements (with limited storage)...... 93 Perpendicular to Ridge...... 68 2.14A Rafter Spans for 20 psf Live Load...... 96 2.5B Lateral Diaphragm Loads from Wind - Parallel to Ridge...... 69 2.14B Rafter Spans for 30 psf Ground Snow Load...... 99 2.5C Lateral Diaphragm Loads from Wind - Parallel to Ridge (Attic/Floor/Ceiling)...... 71 2.14C Rafter Spans for 50 psf Ground Snow Load...... 100 2.6 Lateral Loads from Seismic...... 73 2.14D Rafter Spans for 70 psf Ground Snow 2.7A Floor Joist Spans for 30 psf Live Load...... 74 Load...... 101 2.7B Floor Joist Spans for 40 psf Live Load...... 75 2.15A Roof Framing Capacity Requirements 2.7C Floor Joist Bearing Stresses for Floor for 20 psf Roof Live Load...... 103 Loads...... 76 2.15B Roof Framing Capacity Requirements 2.8A Floor Framing Capacity Requirements for 30 psf Ground Snow Load...... 106 for 30 psf Live Load...... 77 2.15C Roof Framing Capacity Requirements 2.8B Floor Framing Capacity Requirements for 50 psf Ground Snow Load...... 107 for 40 psf Live Load...... 78 2.15D Roof Framing Capacity Requirements 2.9A Exterior Wall Stud Bending Stresses from for 70 psf Ground Snow Load...... 108 Wind Loads...... 80 2.16 Ridge Beam Capacity Requirements for 2.9B Exterior Wall Stud Compression Stresses.... 82 Interior Center Bearing Roof and Ceiling.. 110 2.9C Interior Loadbearing Wall Stud 2.17 Hip and Valley Beam Capacity Compression Stresses from Live Loads...... 84 Requirements...... 111

Table 2.1 Lateral Framing Connection Loads from Wind (For Roof-to-Plate, Plate-to-Plate, Plate-to-Stud, and Plate-to-Floor)

700‐yr. Wind Speed 110 115 120 130 140 150 160 170 180 195 3‐second gust (mph) Wall Height (ft) Unit Framing Loads (plf)1,2,3,4 8 67 73 79 93 108 124 141 159 178 209 10 79 87 94 111 129 148 168 190 212 249 12 91 100 109 128 148 170 193 218 245 287 14 103 112 122 144 167 191 218 246 275 323 16 114 124 135 159 184 212 241 272 305 358 18 124 136 148 174 201 231 263 297 333 391 20 135 147 160 188 218 250 285 321 360 423 1 Tabulated framing loads shall be permitted to be multiplied by 0.92 for framing not located within 3 feet of corners for buildings less than 30 feet in width (W), or within W/10 of corners for buildings greater than 30 feet in width.

2 Tabulated framing loads assume a building located in Exposure B with a mean roof height of 33 feet. For buildings located in other exposures, tabulated values shall be multiplied by the appropriate adjustment factor in Section 2.1.3.1. 3 Tabulated framing loads are specified in pounds per linear foot of wall. To determine connection requirements, multiply the tabulated unit lateral framing load by the multiplier from the table below corresponding to the spacing of the connection: Connection Spacing (in.) 12 16 19.2 24 48 Multiplier 1.00 1.33 1.60 2.00 4.00 4 When calculating lateral loads for ends of headers, girders, and window sills, multiply the tabulated unit lateral load by ½ of the header, girder, or sill span (ft).

ASCE Footnote 3) . 2 (WFCM Table 2.1 (WFCM Table (WFCM Table 2.1) (WFCM Table ) is taken from taken is ) pi

-0.8 - 0.6[(log(A/500)) / (log (10/500))] -0.8 - 0.3[(log(A/500)) / (log(10/500))] +/- 0.18 21.15 (-1.22 - 0.18) 148plf (16 in./12 in./ft) -0.8 - 0.6[(log(133/500)) / (log(10/500))] -1.00 -0.8 - 0.3[(log(133/500)) / (log(10/500))] -0.9 -29.61 psf (Negative pressure denotes denotes pressure -29.61 psf (Negative -29.61(10/2)

suction) 197 lbs = 148 (1.33) |-148 plf|

======

p p pi max GC GC p GC End Zone (-0.9-0.18) / (-1.0-0.18) = 0.92 (WFCM Table 2.1 Footnote 1) 2.1 Footnote (-0.9-0.18) / (-1.0-0.18) = 0.92 (WFCM Table of 92% to reduced be may loads Zone Interior Therefore, tabulated values. Footnote 1: loads are based on End Zone connection framing Lateral Coefficients (Zone 5) per the figure Table of 2.4. Where Interior Zones (Zone 4) occur, connection loads may be of tabulated loads are conservatively Adjustment reduced. ft = 133 A based on a 20' wall height where Interior Zone The ratio of Zone 4 to Zone 5 loads is: The internal pressure coefficient (GC coefficient pressure internal The therefore: to obtain multiplied by half the stud height is The pressure connection load: the unit lateral framing Required capacity of lateral framing connections spaced at 16" o.c. is: Table 26.11-1. 7-10 Table - - - ), the

p AMERICAN WOOD COUNCIL AMERICAN WOOD equation is p . The . The GC 2 . The minimum required minimum The . 2 2 2 2 COMMENTARY TO THE WOOD FRAME CONSTRUCTION MANUAL CONSTRUCTION FRAME WOOD THE TO COMMENTARY pi /3=33.3 /3=33.3 ft 2 Lateral Framing Connection Loads from Wind from Loads Framing Connection Lateral for A ≤ 10 ft for ASCE 7-10 Figure 30.4-1. - qGC

p Lateral framing connection loads at base at loads connection framing Lateral Compute the lateral framing connection framing lateral the Compute bottom of studs based load at the top and loads, using external on tributary wind (end zone) components and cladding pressure internal and coefficients pressure buildings. coefficients for enclosed and top of wall expressed in pounds per wall expressed and top of length. linear foot of wall effective effective wind area equals the tributary For long area of the framing member. and narrow tributary areas, the area width framing the one-third to increased be may load for actual span to account member This results in lower aver distributions. in width The increase age wind pressures. of wind force only to calculation applies coefficients. cients result in higher wind loads relative cients result in higher resisting system to main wind force (MWFRS) coefficients. When determin (GC coefficients pressure C&C ing Components and cladding (C&C) coeffi -0.8 for A > 500 ft -0.8 for -0.8 - 0.6[(log(33.3/500)) / (log (10/500))] -1.22 -1.4 -0.8 - 0.6[(log(A/500)) / (log (10/500))] external pressure coefficients for C&C coefficients for pressure external coefficient for +/- 0.18 internal pressure pressure on the wall pressure 21.15 psf (See Table C1.1) 21.15 psf (See Table for 10 < A ≤ 500 ft for enclosed buildings

======qGC = =

p p p p p p pi q max max GC GC GC GC GC GC p p GC Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized. Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement.

therefore:

ft 13.3 equals area tributary Stud

where: Given -150 mph, Exposure B, 33' MRH, 10' wall height, 16" o.c. connection spacing. Example: Table 2.1 Table Description: determined using 2.4): Table WFCM End Zones (See Zone 5 as shown in Background: Procedure: area for analysis is h is for analysis area WOOD FRAME CONSTRUCTION MANUAL

Table 2.2A Uplift Connection Loads from Wind (For Roof-to-Wall, Wall-to-Wall, and Wall-to-Foundation)

700‐yr. Wind Speed 110 115 120 130 140 150 160 170 180 195 3‐second gust (mph) 2 Roof/Ceiling Assembly Roof Span (ft) Unit Connection Loads (plf)1,2,3,4,5,6,7 Design Dead Load ENGINEERED DESIGN 12 118 128 140 164 190 219 249 281 315 369 24 195 213 232 272 315 362 412 465 521 612 0 psf 8 36 272 298 324 380 441 506 576 650 729 856 48 350 383 417 489 567 651 741 836 938 1100 60 428 468 509 598 693 796 906 1022 1146 1345 12 70 80 92 116 142 171 201 233 267 321 24 111 129 148 188 231 278 328 381 437 528 10 psf 36 152 178 204 260 321 386 456 530 609 736 48 194 227 261 333 411 495 585 680 782 944 60 236 276 317 406 501 604 714 830 954 1153 12 46 56 68 92 118 147 177 209 243 297 24 69 87 106 146 189 236 286 339 395 486 15 psf 36 92 118 144 200 261 326 396 470 549 676 48 116 149 183 255 333 417 507 602 704 866 60 140 180 221 310 405 508 618 734 858 1057 12 22 32 44 68 94 123 153 185 219 273 24 27 45 64 104 147 194 244 297 353 444 20 psf 36 32 58 84 140 201 266 336 410 489 616 48 38 71 105 177 255 339 429 524 626 788 60 44 84 125 214 309 412 522 638 762 961 12 ‐ 8 20 44 70 99 129 161 195 249 24 ‐ 3 22 62 105 152 202 255 311 402 25 psf 36 ‐‐24 80 141 206 276 350 429 556 48 ‐‐27 99 177 261 351 446 548 710 60 ‐‐29 118 213 316 426 542 666 865 1 Tabulated unit uplift connection loads shall be permitted to be multiplied by 0.75 for framing not located within 6 feet of corners for buildings less than 30 feet in width (W), or W/5 for buildings greater than 30 feet in width. 2 Tabulated uplift loads assume a building located in Exposure B with a mean roof height of 33 feet. For buildings located in other exposures, the tabulated values for 0 psf roof dead load shall be multiplied by the appropriate adjustment factor in Section 2.1.3.1 then reduced by the appropriate design dead load. 3 Tabulated uplift loads are specified in pounds per linear foot of wall. To determine connection requirements, multiply the tabulated unit uplift load by the multiplier from the table below corresponding to the spacing of the connectors: Connection Spacing (in.) 12 16 19.2 24 48 Multiplier 1.00 1.33 1.60 2.00 4.00 4 Tabulated uplift loads equal total uplift minus 0.6 of the roof/ceiling assembly design dead load. 5 Tabulated uplift loads are specified for roof‐to‐wall connections. When calculating uplift loads for wall‐to‐wall or wall‐to‐foundation connections, tabulated uplift values shall be permitted to be reduced by 73 plf (0.60 x 121 plf) for each full wall above. 6 When calculating uplift loads for ends of headers/girders, multiply the tabulated unit uplift load by 1/2 of the header/girder span (ft.). Cripple studs need only be attached per typical uplift requirements. 7 For jack rafter uplift connections, use a roof span equal to twice the jack rafter length. The jack rafter length includes the overhang length and the jack span. 8 Tabulated uplift loads for 0 psf design dead load are included for interpolation or use with actual roof dead loads. Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized. AMERICAN WOOD COUNCIL 26 ENGINEERED DESIGN

Table 2.2A Uplift Connection Loads from Wind

Description: Uplift loads at the roof to wall connection. pLR = 21.15 (-0.69 - 0.18) = -18.4 psf

Procedure: Use Main Wind Force Resisting System pLO = 21.15 (-0.69 - 0.18) = -18.4 psf (MWFRS) coefficients to calculate wind uplift forces. Sum moments to compute Since dead loads in this case are resisting uplift forces, maximum uplift force at the roof to wall they are multiplied by 0.6, per ASCE 7-10 section 2.4.1. connection. Thus roof/ceiling dead loads are equal to: (15 psf) 0.6 = 9 psf Background: Per ASCE 7-10, worst case uplift loads occur at a 20 degree roof slope with wind Summing moments about the leeward roof-to-wall inter- perpendicular to the ridge and roof over- section, the uplift forces are calculated for a 1' wide section hang uplift forces included. Roof/ceiling through the building. To parallel the notation above, the gravity loads are included to resist uplift forces retain the WR, WO, etc., notation and are preceded forces. by a V (for vertical) or H (for horizontal): Example: VWO = -35.2(2) = -70.4 lbs Given - 150 mph, Exposure B, 33' MRH, 20 degree roof VWR = -26.4(36 / 2) = -475.2 lbs slope, 36' roof span, 2' overhangs, 15 psf roof/ceiling dead VLR = -18.4(36 / 2) = -331.2 lbs load, 16" o.c. connection spacing. VLO = -18.4(2) = -36.8 lbs External pressure coefficients are taken from ASCE 7-10 HWO = -35.2(2)(tan(20°)) = -25.7 lbs Figure 28.4-1. Internal pressure coefficients are taken from HWR = -26.4(36 / 2)(tan(20°)) = -173.0 lbs ASCE 7-10 Table 26.11-1 and applied to the Windward HLR = -18.4(36 / 2)(tan(20°)) = -120.5 lbs Roof (WR) and Leeward Roof (LR). The pressure coefficient for the bottom surface of the Windward Overhang HLO = -18.4(2)(tan(20°)) = -13.4 lbs (WO) is computed using a gust factor (0.85) and a pressure coefficient (0.7) from sectionsASCE 7-10 sections 26.9.1 and 28.4.3, respectively. The positive internal pressure co- The dead load of the roof, R, is also added: efficient was applied to the bottom surface of the Leeward RWO = 9(2) = 18 lbs Overhang (LO) to model background pressure. RWR = 9(18) = 162 lbs

proof = pressure on the roof portion RLO = 9(2) = 18 lbs RLR = 9(18) = 162 lbs proof = q(GCpf - GCpi), for each portion of the roof where: Summing moments about the leeward top of wall: q = 21.15 psf (See Table C1.1)

ΣML = 0 = [-70.4+18][1+36] + [-475.2+162][9+18] + [-331.2+162][9]- [-36.8+18][1] + [(-25.7) GCpf = external pressure coefficients for MWFRS (0.364)] - [(-173.0)(3.276) ] + [(-120.5)(3.276)]

- [(-13.4)(0.364)] - 36FW GCpi = +/- 0.18 internal pressure coefficient for enclosed buildings Solving for FW: End Zone: FW = -326 plf WO GCpf = -1.07, GCp = (0.85) (-0.7) = -0.60

WR GCpf = -1.07, GCpi = -0.18 Unit uplift connection load is:

LO GCpf = -0.69, GCpi = -0.18 = 326 plf (WFCM Table 2.2A) LR GCpf = -0.69, GCpi = -0.18 Required uplift capacity of connections spaced at 16" o.c. Substituting: = 326 plf (16 in./12in./ft) pWO = 21.15 (-1.07 - 0.60) = -35.2 psf = 434 lbs = 326(1.33) (WFCM Table 2.2A

ENGINEERED DESIGN 2 28 Leeward Wall

Wind Uplift Force Uplift Wind (88 plf) / (118 plf) 0.75

88 plf = 118 plf =

to similar calculation on based force uplift Zone Interior is: exterior zone Reduction factor: Dead Load ) W AMERICAN WOOD COUNCIL AMERICAN WOOD COMMENTARY TO THE WOOD FRAME CONSTRUCTION MANUAL CONSTRUCTION FRAME WOOD THE TO COMMENTARY Uplift Force Reaction (F Reaction Force Uplift

Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized. Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement.

End Zone uplift force is: End Zone uplift force Given - mph, 110 Exposure B, 33' MRH, 20 degree roof dead roof/ceiling psf 0 overhangs, 2' span, roof 12' slope, load, 12" o.c. Footnote 1: Footnote Where pressures. zone end on based are loads Tabulated the requirements of footnote 1 are met, tabulated loads as follows: may be decreased

WOOD FRAME CONSTRUCTION MANUAL

Table 2.9A Exterior Wall Stud Bending Stresses from Wind Loads (Cont.)

700‐yr. Wind Speed 150 160 170 180 195 3‐second gust 2 (mph) Stud Size 2x4 2x6 2x8 2x4 2x6 2x8 2x4 2x6 2x8 2x4 2x6 2x8 2x4 2x6 2x8 ENGINEERED DESIGN Wall Stud Induced f (psi)1,2,3 Height Spacing b 12 in. 903 366 211 1028 416 240 1160 470 270 1301 527 303 1527 618 356 8 ft 16 in. 1205 488 281 1371 555 319 1547 627 361 1735 702 404 2036 824 474 24 in. 1807 732 421 2056 833 479 2321 940 541 2602 1054 606 3054 1237 712 12 in. 1365 553 318 1553 629 362 1754 710 409 1966 796 458 2307 934 538 10 ft 16 in. 1820 737 424 2071 839 483 2338 947 545 2621 1062 611 3077 1246 717 24 in. 2731 1106 636 3107 1258 724 3507 1420 817 3932 1592 916 4615 1869 1076 12 in. 1906 772 444 2168 878 505 2448 991 570 2744 1111 640 3220 1304 751 12 ft 16 in. 2541 1029 592 2891 1171 674 3263 1322 761 3659 1482 853 4294 1739 1001 24 in. 3811 1543 888 4336 1756 1011 4895 1982 1141 5488 2222 1279 ‐ 2608 1501 12 in. 2519 1020 587 2866 1161 668 3236 1310 754 3628 1469 845 4258 1724 992 14 ft 16 in. 3359 1360 783 3822 1548 891 4314 1747 1006 4837 1959 1127 5677 2299 1323 24 in. 5039 2040 1174 5733 2322 1336 ‐ 2621 1508 ‐ 2938 1691 ‐ 3448 1985 12 in. 3203 1297 746 3644 1476 849 4113 1666 959 4612 1868 1075 5412 2192 1261 16 ft 16 in. 4270 1729 995 4858 1967 1132 5485 2221 1278 ‐ 2490 1433 ‐ 2922 1682 24 in. ‐ 2594 1493 ‐ 2951 1698 ‐ 3332 1917 ‐ 3735 2150 ‐ 4383 2523 12 in. 3952 1600 921 4496 1821 1048 5076 2056 1183 5691 2304 1326 ‐ 2705 1556 18 ft 16 in. 5269 2134 1228 5995 2428 1397 ‐ 2741 1577 ‐ 3073 1768 ‐ 3606 2075 24 in. ‐ 3201 1842 ‐ 3642 2096 ‐ 4111 2366 ‐ 4609 2652 ‐ 5409 3113 12 in. 4764 1929 1110 5420 2195 1263 ‐ 2478 1426 ‐ 2778 1599 ‐ 3260 1876 20 ft 16 in. ‐ 2572 1480 ‐ 2927 1684 ‐ 3304 1901 ‐ 3704 2132 ‐ 4347 2502 24 in. ‐ 3859 2221 ‐ 4390 2527 ‐ 4956 2852 ‐ 5556 3198 ‐‐3753 1 Tabulated bending stresses assume a building located in Exposure B with a mean roof height of 33 feet. For buildings located in other exposures, the tabulated values shall be multiplied by the appropriate adjustment factor in Section 2.1.3.1. 2 Tabulated bending stresses shall be permitted to be multiplied by 0.92 for framing not located within 3 feet of corners for buildings less than 30 feet in width (W), or within W/10 of corners for buildings greater than 30 feet in width. 3 The tabulated bending stress (fb) shall be less than or equal to the allowable bending design value (Fb').

Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized. AMERICAN WOOD COUNCIL 29 ENGINEERED DESIGN 2 30 (WFCM Table 2.9A) (WFCM Table

/S (tabulated) M 1,820 psi 464.6 (12)/3.0625 1,820 psi

= = = =

b f b (Tabulated) f Footnote 2: 2.1 for calculation of footnotes. Table See Commentary Example: height, wall 10' MRH, 33' B, Exposure mph, 150 - Given stud spacing. 2x4 studs, 16" o.c. induced wall for exterior 2.10 Table from Calculations bending loads showed the applied moments from wind to be 464.6 ft-lbs. moment for this case stress bending a into moment this bending Substituting calculation: - AMERICAN WOOD COUNCIL AMERICAN WOOD COMMENTARY TO THE WOOD FRAME CONSTRUCTION MANUAL CONSTRUCTION FRAME WOOD THE TO COMMENTARY Exterior Wall Stud Bending Stresses from Wind Loads Wind from Stresses Bending Stud Wall Exterior Bending stress in wall studs due to wind stress in wall studs Bending Compute wind pressures using C&C coef very high. Defining the effective wind studthe wall of area tributary area and the is key to computing the design suction. Stud span equals the wall height minus plates. bottom and top the of thickness the For a nominal 8' wall, the height is: 97 1/8" - 4.5" = 92 3/8". Two cases have been checked in these tables. For C&C are wind pressures, the bending stresses stresses. of axial computed independent In addition, the case in which bending stresses from MWFRS pressures act in axial stresses from windcombination with and gravity loads must be analyzed. For conditions in this to the limited buildings stud control the C&C loads the Manual, design. load. ficients and calculate stud requirements. ficients and calculate As in Table 2.4, peak suction forces are

Table 2.10 Exterior Wall Induced Moments from Wind Loads

700‐yr. Wind Speed 110 115 120 130 140 150 160 170 180 195 3‐second gust (mph) 2 Stud Wall Height Induced Moment (ft‐lbs)1,2 Spacing ENGINEERED DESIGN 12 in. 124 136 148 173 201 231 262 296 332 390 8 ft 16 in. 165 181 197 231 268 307 350 395 443 520 24 in. 248 271 295 346 402 461 525 592 664 779 12 in. 187 205 223 262 304 348 396 448 502 589 10 ft 16 in. 250 273 297 349 405 465 529 597 669 785 24 in. 375 410 446 523 607 697 793 895 1004 1178 12 in. 262 286 311 365 424 486 553 625 700 822 12 ft 16 in. 349 381 415 487 565 648 738 833 934 1096 24 in. 523 572 622 731 847 973 1107 1249 1401 1644 12 in. 346 378 411 483 560 643 732 826 926 1087 14 ft 16 in. 461 504 549 644 747 857 975 1101 1234 1449 24 in. 692 756 823 966 1120 1286 1463 1652 1852 2173 12 in. 440 480 523 614 712 817 930 1050 1177 1381 16 ft 16 in. 586 641 697 819 949 1090 1240 1400 1569 1842 24 in. 879 961 1046 1228 1424 1635 1860 2100 2354 2763 12 in. 542 593 645 758 879 1009 1147 1295 1452 1704 18 ft 16 in. 723 790 861 1010 1171 1345 1530 1727 1936 2273 24 in. 1085 1186 1291 1515 1757 2017 2295 2591 2905 3409 12 in. 654 715 778 913 1059 1216 1383 1562 1751 2055 20 ft 16 in. 872 953 1038 1218 1412 1621 1844 2082 2334 2740 24 in. 1308 1429 1556 1826 2118 2432 2767 3123 3502 4110 1 Tabulated induced moments assume a building located in Exposure B with a mean roof height of 33 feet. For buildings located in other exposures , the tabulated values shall be multiplied by the appropriate adjustment factor in Section 2.1.3.1. 2 Tabulated induced moments shall be permitted to be multiplied by 0.92 for framing not located within 3 feet of corners for buildings less than 30 feet in width (W), or within W/10 of corners for buildings greater than 30 feet in width.

Table 2.10 Exterior Wall Induced Moments From Wind Loads

Description: Applied moment on wall due to wind Substituting this uniform load, w, into a bending calcula- loads. tion for a simply supported member:

Procedure: Calculate the applied moment based on 2 wL C&C wind pressures. M = Background: Applied suction force is dependent on 8 3. 375 tributary areas. 39.( 48 10 )2 ()− 12 Example: = Given - 150 mph, Exposure B, 33' MRH, 10' wall height, 8 16" o.c. stud spacing. 466 ft lbs =−

pmax = 29.61 psf (See Commentary to Table 2.1) M(Tabulated) = 466 ft-lbs

w = pmax (16 in./12in./ft) = 39.48 plf (A value of 465ft-lbs is shown in WFCM Table 2.10 – difference due to rounding in calculation of pmax)

Table 2.11 Loadbearing Wall Loads from Snow or Live Loads (For Wall Studs, Headers, and Girders) Dead Load Assumptions: Roof Assembly DL = 20 psf, Wall Assembly DL = 121 plf, Floor Assembly DL = 10 psf, Floor LL = 40 psf

GroundSnowLoad RLL GSL RLL GSL RLL GSL orRoofLiveLoad(psf) 20 30 50 70 20 30 50 70 20 30 50 70

RoofSpan(ft) UnitHeader/GirderBeamLoads(plf)1 12 320 360 493 627 200 260 367 473 240 259 351 443 24 560 613 834 1056 320 405 568 732 480 517 702 887 36 800 867 1178 1489 440 553 776 998 720 776 1053 1330 60 1280 1379 1872 2365 680 782 1089 1407 1200 1293 1755 2217

GroundSnow RLL GSL RLL GSL RLL GSL RLL GSL RLL GSL LoadorRoof LiveLoad(psf) 20 30 50 70 20 30 50 70 20 30 50 70 20 30 50 70 20 30 50 70 RoofSpan(ft) UnitHeader/GirderBeamLoads(plf)1 12 641 671 771 871 521 551 651 778 300* 300* 300* 300* 416 461 541 624 571 585 654 724 24 1091 1130 1297 1463 851 890 1057 1237 600* 600* 600* 600* 641 705 827 950 1021 1049 1188 1326 36 1541 1591 1824 2058 1181 1231 1464 1700 900* 900* 900* 900* 866 951 1118 1284 1471 1513 1721 1929 60 2441 2515 2885 3255 1841 1915 2285 2655 1500* 1500* 1500* 1500* 1316 1392 1623 1862 2371 2441 2787 3134

GroundSnow RLL GSL RLL GSL RLL GSL RLL GSL RLL GSL LoadorRoof LiveLoad(psf) 20 30 50 70 20 30 50 70 20 30 50 70 20 30 50 70 20 30 50 70 RoofSpan(ft) UnitHeader/GirderBeamLoads(plf)1 12 1002* 1032 1132 1232 762 792 892 992 721* 721* 721* 721* 657 702 782 862 962* 962* 1015 1085 24 1722* 1731 1898 2064 1212 1251 1418 1584 1321* 1321* 1321* 1321* 1002 1066 1188 1311 1682* 1682* 1789 1927 36 2442* 2442* 2665 2899 1662 1712 1945 2179 1921* 1921* 1921* 1921* 1362 1432 1599 1765 2402* 2402* 2562 2770 60 3882* 3882* 4206 4576 2562 2636 3006 3376 3121* 3121* 3121* 3121* 2082 2113 2344 2583 3842* 3842* 4108 4455 1 TabulatedloadsassumesimplyͲsupportedsinglespanfloorjoists.Forcontinuoustwospanfloorjoists,loadsoninteriorloadbearingwalls, headers,andgirdersshallbemultipliedby1.25. * Tabulatedunitheader/girderbeamloads(plf)arebasedonthemaximumloadcombination:DeadLoad+FloorLiveLoad(i.e.D+L).Reducedunit loadsarepermittedforloadcombinationsthatincludeRoofLiveLoad(RLL)andGroundSnowLoad(GSL).

AMERICAN WOOD COUNCIL 33 ENGINEERED DESIGN 2 34 load ASCE 7-10 psf) ƚŽďĞƉƉůŝĞĚŝŶĞƐŝŐŶŝŶŐ D 1.15 1.25 1.15 1.00 1.25 g Ip t C psf e combinations were considered. When designing structural wood members, it is also necessary to consider the effect of ORDGGXUDWLRQDVIROORZV Table 2.11, the following the 2.11, Table , the following load combinations were (building width < 40 ft) g ^ƚƌƵĐƚƵƌĂůtŽŽĚDĞŵďĞƌƐ = Ip = 2ft] = 400 plf = 20 psf [(36 ft/2) + = 242 plf = 11 psf (11 ft)(2 walls) = 10 psf (36 ft/2) (2 floors) = 360 plf = 0.7C 'HDG)ORRU/LYH6QRZ snow snow (Snow) (Snow) = 23.1 psf (36ft + 2ft + 2ft)/2 walldead roof dead roof floordead ASCE 7-10 1. Dead + Floor Live 2. Dead + Snow 3. right = (1.0)(30 psf) = 30.0 psf TOTAL = 1,002 plf w 1,002 = w TOTAL 8QEDODQFHG6QRZ/RDG q LOAD COMBINATIONS: Per FRQVLGHUHGIRUWKLVH[DPSOH VQRZORDG LOADS: 'HDG/RDGV w plf 0.7(1.0)(1.1)(1.0)(30 23.1 6QRZ/RDGV 462 = %DODQFHG6QRZ/RDG = = q R 'ŽǀĞƌŶŝŶŐ>ŽĂĚƵƌĂƟŽŶ͕ Header Exterior Wall AMERICAN WOOD COUNCIL AMERICAN WOOD Unbalanced Snow Load COMMENTARY TO THE WOOD FRAME CONSTRUCTION MANUAL CONSTRUCTION FRAME WOOD TO THE COMMENTARY Ridge Floor Dead and Live Loads Floor Dead and Live Loads (For Wall Studs, Headers, and Girders) Studs, Headers, and (For Wall Dead Load Sum gravity loads and calculate wall and wall calculate and loads gravity Sum KHDGHUJLUGHUUHTXLUHPHQWV In calculating the unit header/girder beam header/girder unit the calculating In ORDGVIRUHDFKEXLOGLQJFRQ¿JXUDWLRQLQ HUVIRUVWRU\EXLOGLQJFRQ¿JXUDWLRQV

^ϳͲϭϬ^>ŽĂĚŽŵďŝŶĂƟŽŶƐ ĞĂĚнϬ͘ϳϱ&ůŽŽƌ>ŝǀĞнϬ͘ϳϱ^ŶŽǁ ĞĂĚнϬ͘ϳϱ&ůŽŽƌ>ŝǀĞнϬ͘ϳϱZŽŽĨ>ŝǀĞ ĞĂĚн^ŶŽǁ ĞĂĚн&ůŽŽƌ>ŝǀĞ ĞĂĚнZŽŽĨ>ŝǀĞ Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized. #5 #4 #3 #2 #1 Left Side of Building $VDUHVXOWRIWKHIDFWRUXVHGLQORDGFRPELQDWLRQV DQG DERYH VHYHUDORIWKHPXOWLVWRU\FDVHVLQ7DEOH Load Live Floor + Load Dead the by controlled were 2.11 FDVHDVVKRZQLQWKHH[DPSOHEHORZ Given - Loadbearing wall supporting Roof, Ceiling, & 2 &OHDU6SDQ)ORRUV EXLOGLQJZLGWK RYHUKDQJV[ snow ground psf 30 load, dead roof psf 20 o.c., 12" studs, ORDGSOIZDOOGHDGORDGDQGDSVIÀRRUOLYHORDG Example: Description: gird- and headers, walls, on loads Gravity Table 2.11 2.11 Table Loads or Live Snow From Loads Wall Loadbearing Procedure: Background: ENGINEERED DESIGN

)RUEXLOGLQJZLGWKVJUHDWHUWKDQIW LHIWZLGWKV )ORRU/LYH/RDGV in Table 2.11), a more complex unbalanced snow load- w = 40 psf (36 ft/2)(2 floors) = 1,440 plf LQJLVUHTXLUHGSHUASCE 7-10 which places 30 percent live of the balanced snow load on the windward side of the 6XPPDUL]LQJWKHORDGV roof and 100 percent of the balanced snow load plus a rectangular surcharge snow load on the leeward side of w = 1,002 plf WKHURRI7KLVVXUFKDUJHORDGVSDQVKRUL]RQWDOO\IURPWKH dead (1/2) ULGJHWRDGLVWDQFHHTXDOWRKdS where hd is the roof wfloorlive = 1,440 plf step drift height and S is the slope expressed as the roof

UXQIRUDULVHRIRQH LHIRUDRQVORSH6 wsnow = 467 plf 7KHPDJQLWXGHRIWKLVVXUFKDUJHVQRZORDGLVHTXDO (1/2) to hdJS where J is the unit weight of snow, which is a (YDOXDWLQJWKHORDGFRPELQDWLRQV function of the ground snow load, J p SFI g Dead + Floor Live The slope, S, assumed in calculating the unit header loads = 1,002 + 1,440 IRUEXLOGLQJZLGWKVHTXDOWRIWLQ7DEOHZDVWDNHQ = 2,442 plf WRFRQVHUYDWLYHO\PD[LPL]HWKHUHVXOWLQJXQEDODQFHGVQRZ ORDGRQWKHKHDGHUIRUHDFKEXLOGLQJFRQ¿JXUDWLRQ Dead + Snow = 1,002 + 467 Sum moments about the top of the wall opposite the unbal- = 1,469 plf anced roof snow load. 'HDG)ORRU/LYH6QRZ = 1,002 + 0.75(1,440) + 0.75(467) Mleft = 0 = 2,432 plf

Mleft = [(30.0 psf)(28)][(36 ft/2) + 2] - 36RRight

wtotal = 2,442 plf (WFCM Table 2.11)

Rright(Snow) = 467 plf Unbalanced Case Governs Tabulated values in Table 2.11 denoted with a “*” are in- In accordance with ASCE 7-10, balanced and unbalanced WHQGHGWRPDNHWKHGHVLJQHUDZDUHWKDWWKHVHDUHJRYHUQHG VQRZORDGVDUHFKHFNHGDQGWKHODUJHUXVHGLQWKHFDOFX- by the Dead Load plus Floor Live Load combination. The lation. Unbalanced snow loads are 1.3 (30.0/23.1) times designer should therefore apply the appropriate load dura- larger than balanced snow loads, but only act along one tion factor, CD, of 1.0 when using these loads to design a KDOIRIDGXDOSLWFKHGURRIIRUUDIWHUV RUOHVVLQVSDQ wood header. KRUL]RQWDOSURMHFWHGOHQJWK 7KHUHIRUHIRUIRUFHVDORQJ the exterior, unbalanced snow loads result in the maximum force to the wall.

Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized. AMERICAN WOOD COUNCIL 35 Polling Question 4) Which of the following is true for calculating exterior wall stud stresses per WFCM? a) Compute bending due to C&C wind loads independent of axial b) Analyze bending due to MWFRS loads combined with axial from gravity and wind c) C&C loads control stud design for buildings limited to WFCM conditions d) All of the above

36 WOOD FRAME CONSTRUCTION MANUAL

PRESCRIPTIVE DESIGN 3

3.1 General Provisions 115 3.2 Connections 116 3.3 Floor Systems 119 3.4 Wall Systems 121 3.5 Roof Systems 123 List of Figures 125 List of Tables 146 Appendix A 303

3.1 General Provisions

3.1.1 Prescriptive Requirements EXCEPTION: For roof live loads and ground snow loads less than or equal to 20 psf and 30 The provisions in Chapter 3 establish a specific set of psf, respectively, lumber floor joist cantilevers resistance requirements for buildings meeting the scope supporting load-bearing walls shall not exceed of this document (see 1.1). Tabular wind requirements one‑eighth of the backspan when supporting only are provided for buildings sited in exposure categories a roof load where the roof clear span does not 3 B and C. exceed 28 feet. PRESCRIPTIVE DESIGN 3.1.2 Equivalent Materials and Systems d. Setbacks Setbacks of loadbearing walls on lumber floor joist systems shall not exceed the depth, d, of the The provisions of this Chapter are not intended to joists (see Figure 2.1d). Lumber floor joists shall be lo- preclude the use of other methods or materials of con- cated directly over studs when used in setback conditions struction. When alternative methods or materials are used, supporting loadbearing walls. design loads and capacities shall be determined from the e. Vertical Floor Offsets Vertical floor offsets shall provisions of Chapter 2. be limited to the floor depth, df, (including floor framing members and floor sheathing), and the floor framing 3.1.3 Prescriptive Design Limitations members on each side of the offset shall be lapped or tied together to provide a direct tension tie across the offset, Wood frame buildings built in accordance with Chap- and to transfer diaphragm shear in both orthogonal direc- ter 3 of this document shall be limited to the conditions tions (see Figure 2.1i). of this section (see Table 3). Conditions not complying f. Diaphragm Aspect Ratio Floor diaphragm lengths with Chapter 3 of this document shall be designed in ac- shall be in accordance with Tables 3.16B and 3.16C. cordance with accepted engineering practice in accordance g. Diaphragm Openings Floor diaphragm openings with Chapter 2. shall not exceed the lesser of 12 feet or 50% of the building dimension (see Figure 2.1k). 3.1.3.1 Wind Exposure and Mean Roof Height Tabulated wind requirements in Chapter 3 are provided 3.1.3.3 Wall Systems for exposure categories B and C at a mean roof height of up a. Wall Heights Loadbearing walls shall not exceed to 33 feet. The building shall neither exceed three stories 10 feet in height. Non‑loadbearing walls shall not exceed nor a mean roof height of 33 feet, measured from average 20 feet in height. grade to average roof elevation (see Figure 3.1a). Habitable b. Wall Stud Spacings Wall stud spacings shall not attics shall be considered an additional floor for purposes exceed 24 inches on center. of determining gravity and seismic loads. c. Shear Wall Line Offsets Offsets in a shear wall line within a story shall not exceed 4 feet (see Figure 2.1l).

3.1.3.2 Floor Systems EXCEPTION: Where shear wall line offsets ex- a. Framing Member Spans Single spans of floor ceed these limits, the structure shall be designed framing members shall not exceed 26 feet for lumber joists. as separate structures attached in the plane of the b. Framing Member Spacings Floor framing member offset. Shear wall length for the shared wall shall spacings shall not exceed 24 inches on center for lumber be the sum of the lengths required for the shared joists, I-joists, and floor trusses. wall of each attached structure. For the purpose of c. Cantilevers Lumber floor joist cantilevers support- determining wind loads, the structure shall be per- ing loadbearing walls shall not exceed the depth, d, of the mitted to be considered as a rectangular structure joists (see Figure 2.1a). Lumber floor joist cantilevers with perimeter dimensions which inscribe the total supporting non-loadbearing walls shall be limited to L/4 structure (see Figure 3.1b). Distribution of shear (see Figure 2.1b). Lumber joists shall be located directly loads into shear wall lines shall be proportional over studs when used in cantilever conditions. to the diaphragm area tributary to each shear wall line or by other accepted engineering practice.

8d common nails spaced at a maximum of 6 inches on cen- 3.2.6.3 Non‑Loadbearing Wall Assemblies ter at panel edges and 12 inches on center in the panel field. Rake overhang to wall, wall to wall, and wall to foundation connections shall be in accordance with the 3.2.5.4 Roof Cladding requirements given in Table 3.4C (see Figures 2.1g-h). Roof cladding shall be attached in accordance with Walls which do not support the roof assembly and are at- the manufacturer’s recommendations. tached in accordance with 3.2.1 need no additional uplift connections. 3.2.5.5 Wall Cladding 3 Wall cladding shall be attached in accordance with the 3.2.6.4 Connections around Wall Openings minimum nailing requirements in Table 3.11 or comply 3.2.6.4.1 Header and/or Girder to Stud Connections Header and/or girder to stud connections shall be in accor- with the manufacturer’s recommendations. PRESCRIPTIVE DESIGN dance with the requirements given in Table 3.7. Window 3.2.6 Special Connections sill plate to stud connections shall be in accordance with the requirements given in Table 3.8. 3.2.6.1 Ridge Connection Requirements 3.2.6.4.2 Top and Bottom Plate to Full Height Studs Ridge connections shall be in accordance with the When the number of full height studs required at each end requirements given in Table 3.6. Prescriptive solutions of a header are selected from Table 3.23C, each stud shall for ridge straps are provided in Table A-3.6. Where ridge be connected in accordance with the requirements given in straps are used, they shall attach to opposing rafters. Table 3.5. Prescriptive solutions for top and bottom plate to stud connections are provided in Table 3.5A. EXCEPTION: Ridge straps are not required when collar ties (collar beams) of nominal 1x6 or EXCEPTION: When the number of full height 2x4 lumber are located in the upper third of the studs required at each end of a header are selected attic space and attached to rafters in accordance from Table 3.23D, the capacity of the connection with Table A-3.6. of the top or bottom plate to each full height stud shall be equal to the unit lateral load, w (plf), 3.2.6.2 Jack Rafters given in Table 3.5 times half of the header span, Jack rafters shall be attached to the wall assembly in L/2 (ft), divided by the required number of full accordance with 3.2.2.1 and attached to hip beams in ac- height studs, NFH, selected from Table 3.23D. cordance with Table 3.6. Top or Bottom Plate to Each Full Height Stud Connection = w * (L/2) / NFH

3.3 Floor Systems

3.3.1 Wood Joist Systems 3.3.1.2 Bearing Joists shall bear directly on beams, girders, ledgers, or 3.3.1.1 Floor Joists loadbearing walls or be supported by hangers. Joist bear- Floor joists shall be in accordance with the maximum ing shall not be less than 1-1/2 inches on wood or metal spans for common species and grades of lumber floor joists or 3 inches on masonry (see Figures 3.4a‑e). Beams and specified in Tables 3.18A‑B. girders shall bear on loadbearing walls, piles, concrete or 3.3.1.1.1 Notching and Boring Notches in the top masonry foundations, or beam hangers (see Figure 3.4f). or bottom edge of solid‑sawn joists shall not be located in the middle one‑third of the joist span. Notches in the 3.3.1.3 End Restraint outer thirds of the span shall not exceed one‑sixth of the Restraint against twisting shall be provided at the end actual joist depth, and shall not be longer than one-third of of each joist by fastening to a rim, band joist, header, or the depth of the member. Where notches are made at the other member or by using full‑height blocking between supports, they shall not exceed one‑fourth the actual joist floor joist ends. Fasteners for end restraint shall be pro- depth. Bored holes are limited in diameter to one‑third vided in accordance with Table 3.1 (see Figures 3.4a‑e). the actual joist depth and the edge of the hole shall not be closer than 2 inches to the top or bottom edge of the joist. Bored holes shall not be located closer than 2 inches to a notch (see Figure 3.3a). Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized. AMERICAN WOOD COUNCIL 39 WOOD FRAME CONSTRUCTION MANUAL

3.3.4 Floor Sheathing 3.3.5 Floor Diaphragm Bracing

3.3.4.1 Sheathing Spans For 700-year return period, 3-second gust wind speeds Floor sheathing spans shall not exceed the provisions greater than 130 mph, blocking and connections shall be of Table 3.14. provided at panel edges perpendicular to floor framing members in the first two bays of framing and shall be 3.3.4.2 Sheathing Edge Support spaced at a maximum of 4 feet on center. Nailing require- Edges of floor sheathing shall have approved ments are given in Table 3.1 (see Figure 3.7b). 3 tongue‑and‑groove joints or shall be supported with blocking, unless ¼ inch minimum thickness underlayment or

1½ inches of approved cellular or lightweight concrete is PRESCRIPTIVE DESIGN installed, or unless the finish floor is of ¾ inch wood strip.

3.4 Wall Systems 3.4.1 Exterior Walls EXCEPTION: Reduced stud requirements shall be permitted provided shear walls are not con- 3.4.1.1 Wood Studs tinuous to corners. Framing must be capable of Wall studs shall be in accordance with the maximum transferring axial tension and compression loads spans for common species and grades of walls studs from above and providing adequate backing for specified in Tables 3.20A-B and spaced in accordance with the attachment of sheathing and cladding materi- Table 3.20C. Exterior loadbearing studs shall be limited to als. a height of 10 feet or less between horizontal supports as specified in Table 3.20C. Exterior non-loadbearing studs 3.4.1.2 Top Plates shall be limited to a height of 14 feet or less for 2x4 studs Double top plates shall be provided at the top of all and 20 feet or less for 2x6 and 2x8 studs in accordance exterior stud walls. The double plates shall overlap at with Table 3.20C. corners and at intersections with other exterior or interior loadbearing walls (see Figure 3.8d). Double top plates shall 3.4.1.1.1 Notching and Boring Notches in either edge of studs shall not be located in the middle one‑third of the be lap spliced with end joints offset in accordance with the stud length. Notches in the outer thirds of the stud length minimum requirements given in Table 3.21. shall not exceed 25% of the actual stud depth. Bored holes shall not exceed 40% of the actual stud depth and the edge 3.4.1.3 Bottom Plates of the hole shall not be closer than 5/8 inch to the edge Bottom plates shall not be less than 2 inch nominal of the stud (see Figure 3.3b). Notches and holes shall not thickness and not less than the width of the wall studs. occur in the same cross‑section. Studs shall have full bearing on the bottom plate.

EXCEPTION: Bored holes shall not exceed 60% 3.4.1.4 Wall Openings of the actual stud depth when studs are doubled. Headers shall be provided over all exterior wall openings. Headers shall be supported by wall studs, jack studs, 3.4.1.1.2 Stud Continuity Studs shall be continuous hangers, or framing anchors (see Figures 3.9a‑b). between horizontal supports, including but not limited to: 3.4.1.4.1 Headers Maximum spans for common girders, floor diaphragm assemblies, ceiling diaphragm species of lumber headers and structural glued laminated assemblies, and roof diaphragm assemblies. When attic timber beams used in exterior loadbearing walls shall not floor diaphragm or ceiling diaphragm assemblies are used exceed the lesser of the applicable spans given in Tables to brace gable endwalls, the sheathing and fasteners shall 3.22A‑E and Table 3.23A. Maximum spans for common be as specified in Table 3.15. The framing and connections species of lumber headers used in exterior non‑loadbearing shall be capable of transferring the loads into the ceiling walls shall not exceed spans given in Table 3.23B. or attic floor diaphragm (see Figures 3.7a-b). 3.4.1.4.2 Full Height Studs Full height studs shall 3.4.1.1.3 Corners A minimum of three studs shall be meet the same requirements as exterior wall studs selected provided at each corner of an exterior wall (see Figures in 3.4.1.1 (see Figures 3.9a‑b). The minimum number of 3.8a‑b). full height studs at each end of the header shall not be less

than half the number of studs replaced by the opening, in assemblies, and roof diaphragm assemblies. accordance with Table 3.23C. 3.4.2.2 Top Plates EXCEPTION: The minimum number of full Double top plates shall be provided at the top of all height studs at each end of the header shall be interior loadbearing partition walls. The double plates shall permitted to be reduced in accordance with Table overlap at corners and at intersections with other exterior 3.23D. The capacity of the connection of the top or interior loadbearing walls (see Figure 3.8d). or bottom plate to each full height stud shall be equal to the unit lateral load, w (plf) given in Table 3.4.2.3 Bottom Plates 3.5 times half of the header span, L/2 (ft.), divided Bottom plates shall not be less than 2 inch nominal by the required number of full height studs, NFH, thickness and not less than the width of the wall studs. selected from Table 3.23D. Studs shall have full bearing on the bottom plate.

Top or Bottom Plate to Each Full Height Stud 3.4.2.4 Wall Openings Connection = w * (L/2) / NFH Headers shall be provided over all interior loadbearing wall openings. Headers shall be supported by wall studs, 3.4.1.4.3 Jack Studs Jack studs shall be at least Stud jack studs, joist hangers, or framing anchors. grade lumber. The minimum number of jack studs support- 3.4.2.4.1 Headers Maximum spans for common spe- ing each end of a header shall not be less than jack stud cies of lumber headers and glued laminated beams are requirements given in Table 3.22F (see Figures 3.9a‑b). given in Tables 3.24A‑B. Full height studs selected in accordance with 3.4.1.4.2 3.4.2.4.2 Studs Supporting Header Beams Jack studs shall be permitted to replace an equivalent number of jack shall be at least Stud grade lumber. The minimum number studs, when adequate gravity connections are provided. of jack studs supporting each end of a header shall not be 3.4.1.4.4 Window Sill Plates Maximum spans for less than jack stud requirements given in Table 3.24C (see window sill plates used in exterior walls shall not exceed Figures 3.9a‑b). An equivalent number of full height studs the spans given in Table 3.23B. shall be permitted to replace jack studs, when adequate gravity connections are provided. 3.4.2 Interior Loadbearing Partitions 3.4.3 Interior Non‑Loadbearing Partitions 3.4.2.1 Wood Studs Interior loadbearing studs shall be at least Stud grade 3.4.3.1 Wood Studs lumber. Interior non‑loadbearing studs shall be at least Utility EXCEPTION: Interior loadbearing studs sup- grade lumber. porting only a roof shall be at least Utility grade 3.4.3.1.1 Notching and Boring Notches in studs shall lumber. not exceed 40% of the stud depth. Bored holes shall not exceed 60% of the stud depth and shall not be closer than 3.4.2.1.1 Notching and Boring Notches in either edge 5/8 inch to the edge. Notches and holes shall not occur in of studs shall not be located in the middle one‑third of the the same cross‑section. stud length. Notches in the outer thirds of the stud length shall not exceed 25% of the actual stud depth. Bored holes 3.4.3.2 Top Plates in interior loadbearing studs shall not exceed 40% of the Single or double top plates shall be provided at the actual stud depth and shall not be closer than 5/8 inch to top of all stud walls. the edge. Notches and holes shall not occur in the same cross‑section (see Figure 3.3b). 3.4.3.3 Bottom Plates Bottom plates shall not be less than 2 inch nominal EXCEPTION: Bored holes shall not exceed 60% thickness and not less than the width of the wall studs. of the actual stud depth when studs are doubled. Studs shall have full bearing on the bottom plate. 3.4.2.1.2 Stud Continuity Studs shall be continuous between horizontal supports, including but not limited to: girders, floor diaphragm assemblies, ceiling diaphragm

C3.4.1.2 Top Plates Capacity of top plate splices is typi- “dropped” headers − headers are assumed to be laterally cally controlled by diaphragm chord forces per Table 3.21. supported at ends only. Dropped headers address the case If large shear forces from the upper stories of a structure where the header is not attached directly to the double-top are transferred through the top plates to shear walls at plate framing as shown in Figure C3.4.1.4.1. the bottom story, drag strut forces, as opposed to chord forces, may govern the top plate slice design and should C3.4.4.2 Exterior Shear Walls Minimum length of full be considered. height sheathing on exterior shear walls is provided for wind design in Table 3.17A and for seismic design in C3.4.1.4 Wall Openings Table 3.17C. Minimum lengths are calculated for Table C3.4.1.4.1 Headers Maximum header spans are tabulated 3.17A by assuming a top plate-to-ridge height of 10 feet for both “raised” headers − headers are assumed to be and adjustments for other top plate-to-ridge heights are laterally supported at ends and along their length, and provided in footnote 4.

Figure C3.4.1.4.1 Dropped and Raised Headers

Double Top Plate

Raised Header

Dropped Header

Full Height Stud Jack Stud

Window Sill Plate

Bottom Plate

C3.5 Roof Systems

Wood I-joists and wood trusses are not covered directly in the prescriptive provisions of Chapter 3 since product properties and installation recommendations are manufacturer specific.

Consideration of the stability of deep beams is important to ensure proper product application. Typically, designers assume that perpendicularly framed roof or floor systems provide bracing to prevent beam buckling. However, in many parts of the country, framing practices call for "dropping" a header below the roof or floor framing and then building a short wall between the header and top plate. Figure 1 shows a typical example of this practice – a garage door header. If beam buckling is not considered in the design of a “dropped” header, a performance problem can occur.

Review of “dropped” header applications has been 1" Lateral Deflection conducted under uniform load, single span conditions. Based on this evaluation, the following recommendations have been developed for engineered lumber products.

In addition, provisions in this guide are based on downward uniform vertical loads only and do not account for additional effects due to lateral loads; such as, wind or seismic. The building designer is responsible for accounting for any design effects due to lateral loads.

Fully-Braced Dropped Header Applications Figure 1: 2 ply 1 ¾ in. x 16 in. Under some “dropped” conditions, a header may be Buckled Garage Door Header assumed to be "fully-braced" and a design reduction does not need to be applied to account for buckling. These conditions are illustrated in Figure 2. For example, light duty headers (usually ≤ 12 in. deep), such as those over windows and sliding glass doors, may be considered fully-braced when the height of the wall above is 4 ft.-0 in. or less. The designer may also assume that deeper sections are fully-braced if designed within the constraints outlined in Figure 2.

Other Dropped Header Applications

Dropped headers with multiple spans, non-uniform loading, or with dimensions not addressed by Figure 2 may also be specified by the designer. However, beam stability must be considered in their design. A design example has been provided to illustrate a beam stability calculation in accordance with the 2005 National Design Specification for Wood Construction. A designer also has the option of detailing the header in a manner that provides the required lateral support to prevent beam buckling. Figure 3 illustrates a single span condition where lateral support has been provided by raising the primary structural header to the level of the perpendicular framing.

November 2007 1 / 5

43 WFCM Wood Frame Construction Manual for One- and Two-Family Dwellings 2015 EDITION WORKBOOK Design of Wood Frame Buildings for High Wind, Snow, and Seismic Loads

44 BUILDING DESCRIPTION

Figure 1: Isometric view (roof overhangs not shown).

2015 Wood Frame Construction Manual Workbook 3

BUILDING DESCRIPTION

North

Wall Heights = 9' Windows Finished Grade to Foundation Top = 1' Typical 3'x4'-6" Floor Assembly Height = 1' Foyer 6'x4'-6" Roof Pitch = 7:12 Kitchen 4'x4'-6" House Mean Roof Height = 24.7' Bath 4'x6' Roof Overhangs = 2' Doors Building Length (L) = 40' Typical 3'x7'-6" Building Width (W) = 32' Foyer 6'x7'-6" Top plate to ridge height = 9.3' Kitchen 9'x7'-6" AMERICAN WOOD COUNCIL

4 General Information

LOADS ON THE BUILDING

Structural systems in the WFCM 2015Edition have been sized using dead, live, snow, seismic and wind loads in accordance with ASCE/SEI 7-10 Minimum Design Loads for Buildings and Other Structures.

Lateral Loads:

Wind:

3-second gust wind speed in Exposure Category B (700 yr. return) = 160 mph Seismic:

Simplified Procedure (ASCE 7-10 Section 12.14)

Seismic Design Category (SDC) – (ASCE 7-10 Section 11.4.2 and IRC Subcategory) = D1 Vertical force distribution factor (F) - (ASCE 7-10 Section 12.14.8.1) = 1.2

Gravity Loads*:

Roof: Floors: Roof Dead Load = 10 psf First Floor Live Load = 40 psf

Ground Snow Load, Pg = 30 psf Second Floor Live Load = 30 psf Roof Live Load = 20 psf Attic Floor Live Load = 30 psf Floor Dead Load = 10 psf Ceiling: Roof Ceiling Load = 10 psf Walls:

*Assumptions vary for wind and seismic dead loads Wall Dead Load = 11 psf

Deflection limits per 2015 IRC

Roof Rafters with flexible Ceiling Attached L/Δ = 240 Roof Rafters with no Ceiling Attached L/Δ = 180 Raised Ceiling Joists with flexible finish L/Δ = 240 Floor Joists L/Δ = 360 Exterior Studs (gypsum interior) H/Δ = 180

Note: See comparable deflection limits in 2015 IBC section 2308 for joists and rafters.

AMERICAN WOOD COUNCIL

56 First Story Design

Wall Sheathing

Sheathing and Cladding (WFCM 3.4.4.1)

Choose Exterior Wall Sheathing OR Cladding from Tables 3.13A and 3.13B respectively

Three second gust wind speed (700 yr) and Exposure category: ...... 160 mph Exp. B

Sheathing Type (wood structural panels, fiberboard, board, hardboard): ... WSP Strength Axis to Support (Parallel or Perpendicular): ...... Parallel Stud Spacing: ...... 16 in. Minimum Panel Thickness to resist suction loads: ...... 15/32 in.

LFH = 25 ft

1-2 North Elevation

LFH = 22 ft

1-1 South Elevation

LFH = 25 ft

1-B East Elevation

LFH = 29 ft

1-A West Elevation

AMERICAN WOOD COUNCIL

Wall Framing (cont’d)

Exterior Loadbearing Wall Headers (WFCM 3.4.1.4.1)

Family Room Door

Choose Headers in Loadbearing Walls from Tables 3.22A-E and Table 3.22F Building Width: ...... 32 ft Required Span: ...... 9 ft Ground Snow Load: ...... 30 psf Three second gust wind speed (700 yr.) and Exposure category: ...... 160 mph Exp. B

Headers supporting roof, ceiling, and two center bearing floors Table 3.22D1 (Dropped) Preliminary Header Selection (Gravity Loads): ...... 20F Glulam 3-1/8x13-3/4 Maximum Header/Girder Span (interpolated): ...... 9'-4" Table 3.22D2 (Raised) Preliminary Header Selection (Gravity Loads): ...... 20F Glulam 3-1/8x13-3/4 Maximum Header/Girder Span (interpolated): ...... 9'-9" Table 3.22F Tabulated Number of Jack Studs Required (R+C+2CBF): ...... 5 Roof Span Adjustment (Footnote 1: (W+12)/48): ...... 0.92 Adjusted no. of jack studs required = tabulated x roof span adjustment: ... 5 Table 3.23A (Dropped) Dropped Header Wind Load Check: ...... 20F Glulam 3-1/8x13-3/4 Maximum Header/Girder Span ...... 11'-6" OK Table 3.23C Tabulated Number of Full Height (King) Studs: ...... 4* Reduced Full Height Stud Requirements (Table 3.23D) x/h = 0.15: ...... 3

Final Selection of Header Grade and Size: Gravity Loads Control: ...... 20F Glulam 3-1/8x13-3/4 Number of Jack Studs Required (gravity controlled): ...... 5** Number of Full Height (King) Studs Required (wind controlled): .... 3* (same species / grade as Loadbearing Studs (WFCM 3.4.1.4.2))

Using identical procedures: Foyer header (6' required): ...... 20F Glulam 3-1/8x9-5/8 6'-9" >6' OK Number of Jack Studs Required: ...... 3** Number of Full Height (King) Studs Required:...... 2*

Typical Window headers (3' required): ...... Dropped 2-2x8's 3'-8" >3' OK Typical Window headers (3' required): ...... Raised 2-2x6's 3'-0" >3' OK Number of Jack Studs Required: ...... 2** Number of Full Height (King) Studs Required:...... 1 * Full height studs could be determined based on 24" o.c. spacing from Tables W6.1-W6.2. ** WFCM 3.4.1.4.3 allows jack studs to be replaced with an equivalent number of full height (king) studs if adequate gravity connections are provided.

If all first floor headers align vertically with second floor headers, only one floor is being carried and headers could be designed for more efficiency (Table 3.24A1/A2 adjusted by 1.4 for half the tributary area). However, jack studs still need to be designed for roof, ceiling, and two floors.

49 PRESCRIPTIVE DESIGN

Table 3.22D1 Laterally Unsupported (Dropped) Header Spans for Dropped Exterior Loadbearing Walls (Supporting a Roof, Ceiling, and Two Center Bearing Floors) Dead Load Assumptions: Exterior

Roof/Ceiling Assembly = 20 psf, Floor Assembly = 10psf, Wall Assembly = 121plf, L/DLL=360 Roof Live Load Ground Snow Load 20 psf 30 psf 50 psf 70 psf Building Width (ft) 12 24 36 12 24 36 12 24 36 12 24 36 Headers Size Maximum Header/Girder Spans (ft-in.) for Common Lumber Species1,3,4 Supporting Roof, Ceiling, 1-2x6 2 - 8 2 - 1 1 - 10 2 - 8 2 - 1 1 - 10 2 - 6 2 - 0 1 - 9 2 - 5 1 - 11 1 - 7 and Two 1-2x8 3 - 4 2 - 8 2 - 3 3 - 4 2 - 8 2 - 3 3 - 2 2 - 6 2 - 2 3 - 0 2 - 5 2 - 1 Center 1-2x10 3 - 11 3 - 2 2 - 8 3 - 11 3 - 2 2 - 8 3 - 9 3 - 0 2 - 7 3 - 6 2 - 10 2 - 5 Bearing Floors 1-2x12 4 - 6 3 - 8 3 - 2 4 - 6 3 - 8 3 - 2 4 - 3 3 - 5 3 - 0 4 - 1 3 - 3 2 - 10 2-2x4 2 - 8 2 - 1 1 - 9 2 - 8 2 - 1 1 - 9 2 - 6 2 - 0 1 - 8 2 - 5 1 - 11 1 - 7 2-2x6 3 - 11 3 - 1 2 - 8 3 - 11 3 - 1 2 - 8 3 - 8 3 - 0 2 - 6 3 - 6 2 - 10 2 - 5 2-2x8 4 - 10 3 - 11 3 - 4 4 - 10 3 - 11 3 - 4 4 - 7 3 - 8 3 - 2 4 - 4 3 - 6 3 - 0 2-2x10 5 - 7 4 - 6 3 - 11 5 - 6 4 - 6 3 - 11 5 - 2 4 - 3 3 - 8 5 - 0 4 - 1 3 - 6 2-2x12 6 - 2 5 - 1 4 - 6 6 - 0 5 - 1 4 - 5 5 - 9 4 - 10 4 - 3 5 - 6 4 - 7 4 - 0 3-2x8 5 - 11 4 - 9 4 - 1 5 - 10 4 - 9 4 - 1 5 - 7 4 - 6 3 - 11 5 - 4 4 - 4 3 - 8 3-2x10 6 - 8 5 - 6 4 - 9 6 - 6 5 - 5 4 - 9 6 - 2 5 - 2 4 - 6 5 - 11 4 - 11 4 - 3 3-2x12 7 - 2 6 - 0 5 - 4 7 - 0 5 - 11 5 - 3 6 - 8 5 - 8 5 - 0 6 - 5 5 - 5 4 - 10 4-2x8 6 - 8 5 - 5 4 - 9 6 - 7 5 - 5 4 - 9 6 - 3 5 - 2 4 - 5 6 - 0 4 - 11 4 - 3 4-2x10 7 - 5 6 - 2 5 - 5 7 - 3 6 - 1 5 - 4 6 - 11 5 - 9 5 - 1 6 - 8 5 - 6 4 - 10 4-2x12 7 - 11 6 - 8 6 - 0 7 - 9 6 - 7 5 - 10 7 - 5 6 - 3 5 - 7 7 - 2 6 - 0 5 - 4 Size Maximum Header/Girder Spans (ft-in.) for Glued Laminated Timber Beams2,3,4 3.125x5.500 5 - 5 4 - 4 3 - 8 5 - 5 4 - 4 3 - 8 5 - 2 4 - 1 3 - 6 4 - 11 3 - 11 3 - 4 3.125x6.875 6 - 9 5 - 5 4 - 7 6 - 9 5 - 5 4 - 7 6 - 5 5 - 2 4 - 5 6 - 1 4 - 10 4 - 2 3.125x8.250 8 - 1 6 - 5 5 - 6 8 - 1 6 - 5 5 - 6 7 - 8 6 - 2 5 - 3 7 - 4 5 - 10 5 - 0 3.125x9.625 9 - 5 7 - 6 6 - 5 9 - 5 7 - 6 6 - 5 8 - 11 7 - 1 6 - 1 8 - 6 6 - 9 5 - 9 3.125x11.000 10 - 8 8 - 6 7 - 3 10 - 8 8 - 6 7 - 3 10 - 1 8 - 1 6 - 11 9 - 7 7 - 8 6 - 6 3.125x12.375 11 - 9 9 - 5 8 - 1 11 - 8 9 - 5 8 - 1 11 - 1 8 - 11 7 - 8 10 - 7 8 - 6 7 - 3 3.125x13.750 12 - 9 10 - 4 8 - 11 12 - 6 10 - 3 8 - 11 11 - 11 9 - 9 8 - 5 11 - 5 9 - 3 8 - 0 3.125x15.125 13 - 6 11 - 1 9 - 7 13 - 2 11 - 0 9 - 7 12 - 7 10 - 5 9 - 1 12 - 1 9 - 11 8 - 7 3.125x16.500 14 - 0 11 - 9 10 - 3 13 - 8 11 - 6 10 - 1 13 - 1 10 - 11 9 - 7 12 - 7 10 - 5 9 - 2 3.125x17.875 14 - 5 12 - 2 10 - 9 14 - 2 11 - 11 10 - 7 13 - 6 11 - 4 10 - 0 13 - 0 10 - 10 9 - 7 3.125x19.250 14 - 10 12 - 6 11 - 1 14 - 7 12 - 3 10 - 11 13 - 11 11 - 9 10 - 5 13 - 5 11 - 3 10 - 0 3.125x20.625 15 - 2 12 - 9 11 - 5 14 - 11 12 - 7 11 - 3 14 - 3 12 - 0 10 - 9 13 - 9 11 - 7 10 - 4 3.125x22.000 15 - 6 13 - 1 11 - 8 15 - 3 12 - 11 11 - 7 14 - 7 12 - 4 11 - 0 14 - 0 11 - 10 10 - 7 3.125x23.375 15 - 9 13 - 4 12 - 0 15 - 6 13 - 2 11 - 10 14 - 10 12 - 7 11 - 4 14 - 4 12 - 2 10 - 10 3.125x24.750 16 - 1 13 - 7 12 - 3 15 - 10 13 - 5 12 - 1 15 - 2 12 - 11 11 - 7 14 - 7 12 - 5 11 - 1 5.125x5.500 7 - 0 5 - 6 4 - 9 7 - 0 5 - 6 4 - 9 6 - 8 5 - 3 4 - 6 6 - 4 5 - 0 4 - 3 5.125x6.875 8 - 9 6 - 11 5 - 11 8 - 9 6 - 11 5 - 11 8 - 4 6 - 7 5 - 8 7 - 10 6 - 3 5 - 4 5.125x8.250 10 - 6 8 - 3 7 - 1 10 - 6 8 - 3 7 - 1 9 - 11 7 - 11 6 - 9 9 - 5 7 - 6 6 - 5 5.125x9.625 12 - 2 9 - 8 8 - 3 12 - 2 9 - 8 8 - 3 11 - 7 9 - 2 7 - 10 11 - 0 8 - 8 7 - 5 5.125x11.000 13 - 11 11 - 0 9 - 5 13 - 11 11 - 0 9 - 5 13 - 2 10 - 6 9 - 0 12 - 6 9 - 11 8 - 6 5.125x12.375 15 - 7 12 - 4 10 - 7 15 - 7 12 - 4 10 - 7 14 - 9 11 - 9 10 - 1 14 - 0 11 - 2 9 - 6 5.125x13.750 17 - 3 13 - 8 11 - 8 17 - 3 13 - 8 11 - 8 16 - 4 13 - 0 11 - 2 15 - 6 12 - 4 10 - 7 5.125x15.125 18 - 10 15 - 0 12 - 10 18 - 10 15 - 0 12 - 10 17 - 10 14 - 3 12 - 3 16 - 11 13 - 6 11 - 7 5.125x16.500 20-0† 16 - 3 13 - 11 20-0† 16 - 3 13 - 11 19 - 3 15 - 5 13 - 3 18 - 4 14 - 8 12 - 7 5.125x17.875 20-0† 17 - 6 15 - 0 20-0† 17 - 6 15 - 0 20-0† 16 - 7 14 - 3 19 - 7 15 - 9 13 - 6 5.125x19.250 20-0† 18 - 8 16 - 1 20-0† 18 - 8 16 - 1 20-0† 17 - 8 15 - 3 20-0† 16 - 9 14 - 5 5.125x20.625 20-0† 19 - 9 17 - 1 20-0† 19 - 8 17 - 1 20-0† 18 - 8 16 - 2 20-0† 17 - 9 15 - 4 5.125x22.000 20-0† 20-0† 18 - 0 20-0† 20-0† 18 - 0 20-0† 19 - 6 17 - 0 20-0† 18 - 7 16 - 2 5.125x23.375 20-0† 20-0† 18 - 10 20-0† 20-0† 18 - 8 20-0† 20-0† 17 - 8 20-0† 19 - 4 16 - 10 5.125x24.750 20-0† 20-0† 19 - 7 20-0† 20-0† 19 - 4 20-0† 20-0† 18 - 4 20-0† 20 - 0 17 - 6 † Spans are limited† toSpans 20 feet are in length. limited to 20 feet in length. 1 Tabulated spans are based on the lowest Fb, Fv, and E for #2 Grade Douglas Fir-Larch, Hem-Fir, Southern Pine, and Spruce-Pine-Fir. For #3 Grade lumber, spans shall be multiplied by 0.75. 1 Tabulated spans are based on #2 Grade Hem-Fir, and are applicable to species with equal or greater Fb and E from the NDS 2 Tabulated spans assume 20F combination glulam with a minimum Fbx=2,000psi, Fvx=210psi, and E=1,500,000psi. 3 The number of jackSupplement studs required (i.e.,at each Douglas end of the Fir-Larch, header shall Southern be determined Pine, from or Table Spruce-Pine-Fir). 3.22F. For #3 Grade lumber, spans shall be multiplied by 0.75. 4 Spans checked2 for Tabulatedlive load deflection spans only. assume 20F combination glulam with a minimum F =2,000psi, F =210psi, and E=1,500,000psi. Copyright © American Wood Council. Downloaded/printed pursuant to Licensebx Agreement.vx No reproduction or transfer authorized. 3 The number of jack studs required at each endAMERICAN of the header WOOD shall COUNCIL be determined from Table 3.22F. 50 WOOD FRAME CONSTRUCTION MANUAL

Table 3.22D2 Laterally Supported (Raised) Header Spans for Exterior Raised Loadbearing Walls (Supporting a Roof, Ceiling, and Two Center Bearing Floors) Dead Load Assumptions: Exterior

Roof, Ceiling, 1-2x6 2 - 8 2 - 1 1 - 10 2 - 8 2 - 1 1 - 10 2 - 7 2 - 0 1 - 9 2 - 5 1 - 11 1 - 8 PRESCRIPTIVE DESIGN and Two 1-2x8 3 - 5 2 - 8 2 - 4 3 - 5 2 - 8 2 - 4 3 - 3 2 - 7 2 - 2 3 - 1 2 - 5 2 - 1 Center 1-2x10 4 - 0 3 - 2 2 - 9 4 - 0 3 - 2 2 - 9 3 - 10 3 - 1 2 - 7 3 - 8 2 - 11 2 - 5 Bearing Floors 1-2x12 4 - 9 3 - 9 3 - 2 4 - 9 3 - 9 3 - 2 4 - 6 3 - 7 3 - 1 4 - 3 3 - 5 2 - 11 2-2x4 2 - 8 2 - 1 1 - 9 2 - 8 2 - 1 1 - 9 2 - 6 2 - 0 1 - 8 2 - 5 1 - 11 1 - 7 2-2x6 4 - 0 3 - 2 2 - 8 4 - 0 3 - 2 2 - 8 3 - 9 3 - 0 2 - 7 3 - 7 2 - 10 2 - 5 2-2x8 5 - 0 4 - 0 3 - 5 5 - 0 4 - 0 3 - 5 4 - 10 3 - 10 3 - 3 4 - 7 3 - 7 3 - 1 2-2x10 6 - 0 4 - 9 4 - 0 6 - 0 4 - 9 4 - 0 5 - 8 4 - 6 3 - 10 5 - 5 4 - 3 3 - 8 2-2x12 7 - 0 5 - 7 4 - 9 7 - 0 5 - 7 4 - 9 6 - 8 5 - 4 4 - 6 6 - 4 5 - 0 4 - 3 3-2x8 6 - 4 5 - 0 4 - 3 6 - 4 5 - 0 4 - 3 6 - 0 4 - 9 4 - 1 5 - 8 4 - 6 3 - 10 3-2x10 7 - 6 5 - 11 5 - 1 7 - 6 5 - 11 5 - 1 7 - 1 5 - 8 4 - 10 6 - 9 5 - 4 4 - 7 3-2x12 8 - 10 7 - 0 5 - 11 8 - 10 7 - 0 5 - 11 8 - 5 6 - 8 5 - 8 8 - 0 6 - 4 5 - 4 4-2x8 7 - 3 5 - 9 4 - 11 7 - 3 5 - 9 4 - 11 6 - 11 5 - 6 4 - 8 6 - 7 5 - 2 4 - 5 4-2x10 8 - 8 6 - 10 5 - 10 8 - 8 6 - 10 5 - 10 8 - 3 6 - 6 5 - 7 7 - 10 6 - 2 5 - 3 4-2x12 10 - 2 8 - 1 6 - 10 10 - 2 8 - 1 6 - 10 9 - 8 7 - 8 6 - 7 9 - 2 7 - 3 6 - 2 Size Maximum Header/Girder Spans (ft-in.) for Glued Laminated Timber Beams2,3,4 3.125x5.500 5 - 6 4 - 4 3 - 8 5 - 6 4 - 4 3 - 8 5 - 2 4 - 2 3 - 6 4 - 11 3 - 11 3 - 4 3.125x6.875 6 - 10 5 - 5 4 - 7 6 - 10 5 - 5 4 - 7 6 - 6 5 - 2 4 - 5 6 - 2 4 - 11 4 - 2 3.125x8.250 8 - 2 6 - 6 5 - 6 8 - 2 6 - 6 5 - 6 7 - 10 6 - 2 5 - 3 7 - 5 5 - 10 5 - 0 3.125x9.625 9 - 7 7 - 7 6 - 6 9 - 7 7 - 7 6 - 6 9 - 1 7 - 3 6 - 2 8 - 8 6 - 10 5 - 10 3.125x11.000 10 - 11 8 - 8 7 - 5 10 - 11 8 - 8 7 - 5 10 - 5 8 - 3 7 - 1 9 - 10 7 - 10 6 - 8 3.125x12.375 12 - 4 9 - 9 8 - 4 12 - 4 9 - 9 8 - 4 11 - 9 9 - 3 7 - 11 11 - 1 8 - 9 7 - 6 3.125x13.750 13 - 8 10 - 10 9 - 3 13 - 8 10 - 10 9 - 3 13 - 0 10 - 4 8 - 10 12 - 4 9 - 9 8 - 4 3.125x15.125 15 - 1 11 - 11 10 - 2 15 - 1 11 - 11 10 - 2 14 - 4 11 - 4 9 - 8 13 - 7 10 - 9 9 - 2 3.125x16.500 16 - 5 13 - 0 11 - 1 16 - 5 13 - 0 11 - 1 15 - 7 12 - 5 10 - 7 14 - 10 11 - 9 10 - 0 3.125x17.875 17 - 9 14 - 1 12 - 0 17 - 9 14 - 1 12 - 0 16 - 11 13 - 5 11 - 5 16 - 0 12 - 8 10 - 10 3.125x19.250 19 - 2 15 - 2 12 - 11 19 - 2 15 - 2 12 - 11 18 - 3 14 - 5 12 - 4 17 - 3 13 - 8 11 - 8 3.125x20.625 20-0† 16 - 3 13 - 10 20-0† 16 - 3 13 - 10 19 - 6 15 - 6 13 - 3 18 - 6 14 - 8 12 - 6 3.125x22.000 20-0† 17 - 4 14 - 9 20-0† 17 - 4 14 - 9 20-0† 16 - 6 14 - 1 19 - 8 15 - 7 13 - 4 3.125x23.375 20-0† 18 - 4 15 - 8 20-0† 18 - 4 15 - 8 20-0† 17 - 7 15 - 0 20-0† 16 - 7 14 - 2 3.125x24.750 20-0† 19 - 4 16 - 7 20-0† 19 - 4 16 - 7 20-0† 18 - 6 15 - 10 20-0† 17 - 6 15 - 0 5.125x5.500 7 - 0 5 - 6 4 - 9 7 - 0 5 - 6 4 - 9 6 - 8 5 - 3 4 - 6 6 - 4 5 - 0 4 - 3 5.125x6.875 8 - 9 6 - 11 5 - 11 8 - 9 6 - 11 5 - 11 8 - 4 6 - 7 5 - 8 7 - 11 6 - 3 5 - 4 5.125x8.250 10 - 6 8 - 4 7 - 1 10 - 6 8 - 4 7 - 1 10 - 0 7 - 11 6 - 9 9 - 6 7 - 6 6 - 5 5.125x9.625 12 - 3 9 - 8 8 - 3 12 - 3 9 - 8 8 - 3 11 - 8 9 - 3 7 - 11 11 - 1 8 - 9 7 - 6 5.125x11.000 14 - 0 11 - 1 9 - 5 14 - 0 11 - 1 9 - 5 13 - 4 10 - 7 9 - 0 12 - 8 10 - 0 8 - 6 5.125x12.375 15 - 9 12 - 6 10 - 8 15 - 9 12 - 6 10 - 8 15 - 0 11 - 11 10 - 2 14 - 3 11 - 3 9 - 7 5.125x13.750 17 - 6 13 - 10 11 - 10 17 - 6 13 - 10 11 - 10 16 - 8 13 - 3 11 - 3 15 - 10 12 - 6 10 - 8 5.125x15.125 19 - 2 15 - 3 13 - 0 19 - 2 15 - 3 13 - 0 18 - 3 14 - 6 12 - 5 17 - 4 13 - 9 11 - 9 5.125x16.500 20-0† 16 - 7 14 - 2 20-0† 16 - 7 14 - 2 19 - 9 15 - 10 13 - 6 18 - 9 15 - 0 12 - 10 5.125x17.875 20-0† 17 - 10 15 - 4 20-0† 17 - 10 15 - 4 20-0† 17 - 0 14 - 8 20-0† 16 - 2 13 - 10 5.125x19.250 20-0† 19 - 0 16 - 4 20-0† 19 - 0 16 - 4 20-0† 18 - 2 15 - 8 20-0† 17 - 3 14 - 10 5.125x20.625 20-0† 20-0† 17 - 5 20-0† 20-0† 17 - 5 20-0† 19 - 4 16 - 8 20-0† 18 - 5 15 - 9 5.125x22.000 20-0† 20-0† 18 - 6 20-0† 20-0† 18 - 6 20-0† 20-0† 17 - 8 20-0† 19 - 6 16 - 9 5.125x23.375 20-0† 20-0† 19 - 6 20-0† 20-0† 19 - 6 20-0† 20-0† 18 - 8 20-0† 20-0† 17 - 8 5.125x24.750 20-0† 20-0† 20-0† 20-0† 20-0† 20-0† 20-0† 20-0† 19 - 8 20-0† 20-0† 18 - 7 † Spans are limited† toSpans 20 feet are in length. limited to 20 feet in length. 1 Tabulated spans are based on the lowest F , F , and E for #2 Grade Douglas Fir-Larch, Hem-Fir, Southern Pine, and Spruce-Pine-Fir. For #3 Grade lumber, spans shall be multiplied by 0.75. 1 Tabulated spans areb basedv on #2 Grade Hem-Fir, and are applicable to species with equal or greater F and E from the NDS 2 Tabulated spans assume 20F combination glulam with a minimum Fbx=2,000psi, Fvx=210psi, and E=1,500,000psi. b 3 The number of jackSupplement studs required (i.e.,at each Douglas end of the Fir-Larch, header shall Southern be determined Pine, from or Table Spruce-Pine-Fir). 3.22F. For #3 Grade lumber, spans shall be multiplied by 0.75. 4 Spans checked2 forTabulated live load deflection spans only. assume 20F combination glulam with a minimum F =2,000psi, F =210psi, and E=1,500,000psi. Copyright © American Wood Council. Downloaded/printed pursuant to Licensebx Agreement.vx No reproduction or transfer authorized. 3 The number of jack studs required at each endAMERICAN of the header WOOD shall COUNCIL be determined from Table 3.22F. 51 PRESCRIPTIVE DESIGN

Table 3.22F Jack Stud Requirements for Headers in Exterior Loadbearing Walls

Roof Live Load Ground Snow Load 20 psf 30 psf 50 psf 70 psf Header Width 3" 4.5" 5" 6" 3" 4.5" 5" 6" 3" 4.5" 5" 6" 3" 4.5" 5" 6" (2‐2x) (3‐2x) (4‐2x) (2‐2x) (3‐2x) (4‐2x) (2‐2x) (3‐2x) (4‐2x) (2‐2x) (3‐2x) (4‐2x) Header Header Number of Jack Studs Required at Each End of the Header1,2,3 Supporting Span (ft) Roof and 2 1111111111111111 Ceiling 4 1111111121112211 6 2111211122213222 8 2221222132224322 10 3222322243225333 12 3222322243325433 14 4322432254336443 16 4332433264437544 18 4332533364438554 20 5333543375449655 Roof, Ceiling, 2 1111111111111111 and One 4 2111211122112221 Center Bearing 6 2221322232223222 Floor 8 3222322243224332 10 4322433253335433 12 4332533354336443 14 5433543364437544 16 6443644375448554 18 6443754485549665 20 75447554965510765 Roof, Ceiling, 2 1111111121112111 and One Clear 4 2221222132223222 Span Floor 6 3222322243224332 8 4332433253335433 10 5333533364436443 12 6443644375447554 14 6443754485548654 16 75547554965510765 18 865486541076511776 20 966596651177612876 Roof, Ceiling, 2 1111111121112111 and Two 4 2221222132223222 Center Bearing 6 3222322243224332 Floors 8 4332433253335433 10 5433543364436443 12 6443644375448554 14 7544754485549665 16 85548654966510765 18 965596651076511876 20 10765107651187612886 Roof, Ceiling, 2 2111211121112211 and Two Clear 4 3222322232224322 Span Floors 6 5333533353335433 8 6443644364437544 10 7554755485548654 12 96559655966510765 14 10765107651177612876 16 11876118761288613987 18 139871398714987151098 20 14 9 9 7 14 9 9 7 15 10 9 8 16 11 10 8 1 Jack stud requirements are based on a roof span (W) of 36 feet. For other roof spans, the tabulated number of jack studs required at each end of the header shall be multiplied by (W + 12)/48. 2 Where the number of jack studs equals 1, the header shall be permitted to be supported by a framing anchor attached to the full‐height wall stud. 3 An equivalent number of full height studs are permitted to replace jack studs, when adequate gravity connections are provided.

Table 3.23A Laterally Unsupported (Dropped) Header Spans for Exterior Loadbearing Walls Resisting Wind Loads Exposure B Dropped

700-yr. Wind Speed 110 115 120 130 140 150 160 170 180 195 3-second gust (mph) Size Maximum Header/Girder Spans (ft-in.) for Common Lumber Species1,2,3,5 1-2x6 5 - 8 5 - 5 5 - 2 4 - 9 4 - 5 4 - 2 3 - 11 3 - 8 3 - 5 3 - 2 1-2x8 6 - 3 6 - 0 5 - 9 5 - 3 4 - 11 4 - 7 4 - 3 4 - 0 3 - 10 3 - 6 3 1-2x10 6 - 8 6 - 5 6 - 2 5 - 8 5 - 3 4 - 11 4 - 7 4 - 4 4 - 1 3 - 9 1-2x12 7 - 2 6 - 10 6 - 7 6 - 1 5 - 7 5 - 3 4 - 11 4 - 7 4 - 4 4 - 0

2-2x4 6 - 6 6 - 3 6 - 0 5 - 6 5 - 2 4 - 9 4 - 6 4 - 3 4 - 0 3 - 8 PRESCRIPTIVE DESIGN 2-2x6 8 - 0 7 - 8 7 - 4 6 - 9 6 - 3 5 - 10 5 - 6 5 - 2 4 - 11 4 - 6 2-2x8 8 - 10 8 - 5 8 - 1 7 - 6 6 - 11 6 - 6 6 - 1 5 - 8 5 - 5 5 - 0 2-2x10 9 - 6 9 - 1 8 - 8 8 - 0 7 - 5 6 - 11 6 - 6 6 - 1 5 - 9 5 - 4 2-2x12 10 - 1 9 - 8 9 - 3 8 - 7 7 - 11 7 - 5 6 - 11 6 - 6 6 - 2 5 - 8 3-2x8 10 - 10 10 - 4 9 - 11 9 - 2 8 - 6 7 - 11 7 - 5 7 - 0 6 - 7 6 - 1 3-2x10 11 - 7 11 - 1 10 - 7 9 - 10 9 - 1 8 - 6 8 - 0 7 - 6 7 - 1 6 - 6 3-2x12 12 - 4 11 - 10 11 - 4 10 - 6 9 - 9 9 - 1 8 - 6 8 - 0 7 - 7 7 - 0 4-2x8 12 - 6 11 - 11 11 - 5 10 - 7 9 - 10 9 - 2 8 - 7 8 - 1 7 - 7 7 - 0 4-2x10 13 - 5 12 - 10 12 - 3 11 - 4 10 - 6 9 - 10 9 - 2 8 - 8 8 - 2 7 - 7 4-2x12 14 - 3 13 - 8 13 - 1 12 - 1 11 - 3 10 - 6 9 - 10 9 - 3 8 - 9 8 - 1 Size Maximum Header/Girder Spans (ft-in.) for Glued Laminated Timber Beams1,2,4,5 3.125x5.500 10 - 7 10 - 1 9 - 8 8 - 11 8 - 4 7 - 9 7 - 3 6 - 10 6 - 5 6 - 0 3.125x6.875 11 - 10 11 - 4 10 - 10 10 - 0 9 - 3 8 - 8 8 - 1 7 - 8 7 - 3 6 - 8 3.125x8.250 12 - 11 12 - 5 11 - 10 11 - 0 10 - 2 9 - 6 8 - 11 8 - 4 7 - 11 7 - 4 3.125x9.625 14 - 0 13 - 4 12 - 10 11 - 10 11 - 0 10 - 3 9 - 7 9 - 1 8 - 7 7 - 11 3.125x11.000 14 - 11 14 - 4 13 - 8 12 - 8 11 - 9 11 - 0 10 - 3 9 - 8 9 - 2 8 - 5 3.125x12.375 15 - 10 15 - 2 14 - 6 13 - 5 12 - 5 11 - 7 10 - 11 10 - 3 9 - 8 8 - 11 3.125x13.750 16 - 8 16 - 0 15 - 4 14 - 2 13 - 2 12 - 3 11 - 6 10 - 10 10 - 3 9 - 5 3.125x15.125 17 - 6 16 - 9 16 - 1 14 - 10 13 - 9 12 - 10 12 - 1 11 - 4 10 - 9 9 - 11 3.125x16.500 18 - 4 17 - 6 16 - 9 15 - 6 14 - 5 13 - 5 12 - 7 11 - 10 11 - 2 10 - 4 3.125x17.875 19 - 1 18 - 3 17 - 6 16 - 1 15 - 0 14 - 0 13 - 1 12 - 4 11 - 8 10 - 9 3.125x19.250 19 - 9 18 - 11 18 - 1 16 - 9 15 - 6 14 - 6 13 - 7 12 - 10 12 - 1 11 - 2 3.125x20.625 20-0† 19 - 7 18 - 9 17 - 4 16 - 1 15 - 0 14 - 1 13 - 3 12 - 6 11 - 7 3.125x22.000 20-0† 20-0† 19 - 4 17 - 11 16 - 7 15 - 6 14 - 6 13 - 8 12 - 11 11 - 11 3.125x23.375 20-0† 20-0† 20 - 0 18 - 5 17 - 1 16 - 0 15 - 0 14 - 1 13 - 4 12 - 3 3.125x24.750 20-0† 20-0† 20-0† 19 - 0 17 - 7 16 - 5 15 - 5 14 - 6 13 - 8 12 - 8 5.125x5.500 16 - 11 16 - 2 15 - 6 14 - 3 13 - 3 12 - 5 11 - 7 10 - 11 10 - 4 9 - 6 5.125x6.875 18 - 10 18 - 1 17 - 4 16 - 0 14 - 10 13 - 10 13 - 0 12 - 3 11 - 6 10 - 8 5.125x8.250 20-0† 19 - 9 18 - 11 17 - 6 16 - 3 15 - 2 14 - 3 13 - 4 12 - 8 11 - 8 5.125x9.625 20-0† 20-0† 20-0† 18 - 11 17 - 6 16 - 4 15 - 4 14 - 5 13 - 8 12 - 7 5.125x11.000 20-0† 20-0† 20-0† 20-0† 18 - 9 17 - 6 16 - 5 15 - 5 14 - 7 13 - 6 5.125x12.375 20-0† 20-0† 20-0† 20-0† 19 - 11 18 - 7 17 - 5 16 - 5 15 - 6 14 - 3 5.125x13.750 20-0† 20-0† 20-0† 20-0† 20-0† 19 - 7 18 - 4 17 - 3 16 - 4 15 - 1 5.125x15.125 20-0† 20-0† 20-0† 20-0† 20-0† 20-0† 19 - 3 18 - 1 17 - 1 15 - 9 5.125x16.500 20-0† 20-0† 20-0† 20-0† 20-0† 20-0† 20-0† 18 - 11 17 - 10 16 - 6 5.125x17.875 20-0† 20-0† 20-0† 20-0† 20-0† 20-0† 20-0† 19 - 8 18 - 7 17 - 2 5.125x19.250 20-0† 20-0† 20-0† 20-0† 20-0† 20-0† 20-0† 20-0† 19 - 4 17 - 10 5.125x20.625 20-0† 20-0† 20-0† 20-0† 20-0† 20-0† 20-0† 20-0† 20 - 0 18 - 5 5.125x22.000 20-0† 20-0† 20-0† 20-0† 20-0† 20-0† 20-0† 20-0† 20-0† 19 - 0 5.125x23.375 20-0† 20-0† 20-0† 20-0† 20-0† 20-0† 20-0† 20-0† 20-0† 19 - 8 5.125x24.750 20-0† 20-0† 20-0† 20-0† 20-0† 20-0† 20-0† 20-0† 20-0† 20-0† † Spans are limited to 20 feet in length. 1 Tabulated spans shall be permitted to be divided by 0.96, for framing not located within 8 feet of building corners. 2 The number of jack studs required at each end of the header shall be determined from Table 3.22F. 3 Tabulated spans are based on the lowest Fb and E for #2 Grade Douglas Fir-Larch, Hem-Fir, Southern PIne, and Spruce-Pine-Fir. 4 Tabulated spans assume 20F combination glulam with a minimum Fby = 800 psi. 5 The number of full height studs required at each end of the header shall be determined in accordance with Table 3.23C. Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized. AMERICAN WOOD COUNCIL 53 PRESCRIPTIVE DESIGN

Table 3.23C Full Height Stud Requirements for Headers or Exposures Window Sill Plates in Exterior Walls Resisting Wind Loads B & C

Wall Stud Spacing (in.) 12 16 24 Number of Full Height Stud Required at Header Span (ft) Each End of the Header1 2 111 4 221 6 332 8 432 10 543 12 653 14 764 16 864 18 975 20 10 8 5 1 The number of full height studs required at each end of the header shall be permitted to be reduced in accordance with the requirements of Section 3.4.1.4.2 and Table 3.23D.

Table 3.23D Reduced Full Height Stud Requirements for Headers Exposures or Window Sill Plates in Exterior Walls Resisting Wind Loads B & C

Distance from Top Plate Down to Header (a) or Distance from Bottom Plate Up to Window Sill Plate (b) to Wall Height (x/h), where x is the larger of a or b 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

Wall Stud 3 Header Span (ft) Number of Full Height Stud Required at Each End of the Header1 Spacing (in.)

2 11111111111 PRESCRIPTIVE DESIGN 4 11222222211 6 12233333221 8 12344444321 10 12455555421 12 12 13466666431 14 13567776531 16 13678887631 18 14689998641 20 14791010109741 2 11111111111 4 11122222111 6 11223332211 8 12233333221 10 12344444321 16 12 12345554321 14 12456665421 16 13466666431 18 13567776531 20 13578887531 2 11111111111 4 11111111111 6 11122222111 8 11222222211 10 11233333211 24 12 12233333221 14 12334443321 16 12344444321 18 12345554321 20 12455555421 1 The capacity of the connection of the top or bottom plate to each full height stud shall be equal to the unit lateral load (w) given on Table 3.5 times half of the header span (L/2) divided by the required number of full height studs (NFH) selected from 3.23D. Top or Bottom Plate to Each Full Height Stud Connection = w*(L/2)/NFH

DoDoubleuble To pTop Plat ePlate

a a

HeHeaderader

FullFu llHeight Height StudStud JackJa ck St Studud

WindowWindow h h SillSill Plate Plate

b b

Boom Plate Bottom Plate

Copyright © American Wood Council. Downloaded/printed pursuant to License Agreement. No reproduction or transfer authorized. AMERICAN WOOD COUNCIL 55 Exterior Non-Loadbearing Wall Headers and Window Sill Plates (WFCM 3.4.1.4.1 and 3.4.1.4.4)

Choose Window Sill Plates from Table 3.23B

Three second gust wind speed (700 yr) and Exposure category: ...... 160 mph Exp. B Required Span: ...... 3 and 4 ft

Selection of Window Sill Plate Grade, and Size: ...... 1-2x6 (flat) Tabulated Window Sill Plate Span: ...... 6'-11" Wall Height Adjustment (Footnote 3: (H/10)1/2): ...... 0.95

Adjusted Maximum Sill Plate Length: Tabulated maximum sill plate Length ÷ Wall Height Adjustment: ..... 7'- 3>" 4' OK

Table 3.23C Number of Full Height (King) Studs Required: ...... 2 Reduced Full Height Stud Requirements (Table 3.23D) x/h = 0.25: ...... 2

Interior Loadbearing Wall Headers (WFCM 3.4.2.4.1)

Living Room Door

Choose Headers for Interior Loadbearing Walls from Tables 3.24A-C Building Width: ...... 32 ft Required Span: ...... 6 ft

Header supporting two center bearing floors Table 3.24B1 (Dropped) Selection of Header Grade and Size: ...... 20F Glulam 3-1/8x9-5/8 Maximum Header/Girder Span (interpolated): ...... 6'-1" ft. > 6' OK

Table 3.24B2 (Raised) Selection of Header Grade and Size: ...... 20F Glulam 3-1/8x9-5/8 Maximum Header/Girder Span (interpolated): ...... 6'-1" ft. > 6' OK Number of Jack Studs Required (Table 3.24C): ...... 4

Using identical procedures: Foyer header (4' required): ...... 2-2x10 4'-0" > 4' OK Number of Jack Studs Required (Table 3.24C): ...... 3

Interior Non-Loadbearing Wall Headers (WFCM 3.4.1.4.1)

Ends of Hallway

The 2015 International Residential Code (IRC) section R602.7.3 allows a single flat 2x4 for interior non- loadbearing walls up to 8' spans.

56 WOOD FRAME CONSTRUCTION MANUAL

Table 3.23B Laterally Unsupported (Dropped) Header Spans for Exterior Non-Loadbearing Walls and Window Sill Plate Exposure B Spans Resisting Wind Loads

700-yr. Wind Speed 110 115 120 130 140 150 160 170 180 195 3-second gust (mph) Maximum Header/Girder Spans for Common Lumber Species1,2,3,4 3 Size (ft-in.) (ft-in.) (ft-in.) (ft-in.) (ft-in.) (ft-in.) (ft-in.) (ft-in.) (ft-in.) (ft-in.)

1-2x4 (flat) 6 - 9 6 - 5 6 - 2 5 - 8 5 - 3 4 - 11 4 - 8 4 - 4 4 - 1 3 - 10 PRESCRIPTIVE DESIGN 1-2x6 (flat) 10 - 1 9 - 8 9 - 3 8 - 6 7 - 11 7 - 5 6 - 11 6 - 6 6 - 2 5 - 8 2-2x4 (flat) 10 - 0 9 - 7 9 - 2 8 - 5 7 - 10 7 - 4 6 - 10 6 - 5 6 - 1 5 - 8 2-2x6 (flat) 15 - 0 14 - 4 13 - 8 12 - 8 11 - 9 11 - 0 10 - 3 9 - 8 9 - 2 8 - 5 1 Tabulated spans shall be permitted to be divided by 0.96, for framing not located within 8 feet of building corners. 2 Tabulated spans are based on 10 foot wall heights. For other wall heights, H, the tabulated spans shall be divided by (H/10)1/2. 3 Tabulated spans are based on the lowest Fb and E for #2 Grade Douglas Fir-Larch, Hem-Fir, Southern PIne, and Spruce-Pine-Fir. 4 The number of full height studs required at each end of the header shall be determined in accordance with Table 3.23C.

Table 3.23B Laterally Unsupported (Dropped) Header Spans for Exposure C Exterior Non-Loadbearing Walls and Window Sill Plate Spans Resisting Wind Loads

700-yr. Wind Speed 110 115 120 130 140 150 160 170 180 195 3-second gust (mph)

Maximum Header/Girder Spans for Common Lumber Species1,2,3,4

Size (ft-in.) (ft-in.) (ft-in.) (ft-in.) (ft-in.) (ft-in.) (ft-in.) (ft-in.) (ft-in.) (ft-in.)

1-2x4 (flat) 5 - 9 5 - 6 5 - 3 4 - 10 4 - 6 4 - 2 3 - 11 3 - 8 3 - 6 3 - 3 1-2x6 (flat) 8 - 7 8 - 2 7 - 10 7 - 3 6 - 9 6 - 3 5 - 11 5 - 6 5 - 3 4 - 10 2-2x4 (flat) 8 - 6 8 - 1 7 - 9 7 - 2 6 - 8 6 - 3 5 - 10 5 - 6 5 - 2 4 - 9 2-2x6 (flat) 12 - 8 12 - 2 11 - 8 10 - 9 10 - 0 9 - 4 8 - 9 8 - 3 7 - 9 7 - 2 1 Tabulated spans shall be permitted to be divided by 0.96, for framing not located within 8 feet of building corners. 2 Tabulated spans are based on 10 foot wall heights. For other wall heights, H, the tabulated spans shall be divided by (H/10)1/2. 3 Tabulated spans are based on the lowest Fb and E for #2 Grade Douglas Fir-Larch, Hem-Fir, Southern PIne, and Spruce-Pine-Fir. 4 The number of full height studs required at each end of the header shall be determined in accordance with Table 3.23C.

Special Connections (WFCM 3.2.6)

Connections around Wall Openings (WFCM 3.2.6.4)

Typical Window

Choose Header/Girder Connections based on loads from Table 3.7 Three second gust wind speed (700 yr) and Exposure category: ...... 160 mph Exp. B Roof Span: ...... 32 ft Header Span (Typical Window): ...... 9 ft

Required Connection Capacity at Each End of Header: Tabulated Uplift Capacity (interpolated): ...... 1636 lbs Floor load adjustment (per footnote 3: 36plf x header span): ...... -324 lbs Adjusted Uplift Capacity ...... 1312 lbs Tabulated Lateral Capacity: ...... 756 lbs

Top/bottom plate to FHS Connection (3.4.1.4.2 Exception) = w*(L/2)/NFH w = 155 plf (Table 3.5); Z' = 125 lbs (Table 3.5A Commentary) Required capacity = 232 lbs. Dividing by Z' yields: ...... 2-16d Commons All shorter headers will require lower capacity.

Using identical procedures: Window (6' header) Adjusted Uplift Capacity (interpolated): ...... 1091 lbs Window (6' header) Tabulated Lateral Capacity: ...... 504 lbs

Window (4' header) Adjusted Uplift Capacity (interpolated): ...... 583 lbs Window (4' header) Tabulated Lateral Capacity: ...... 336 lbs

Window (3' header) Adjusted Uplift Capacity (interpolated): ...... 437 lbs Window (3' header) Tabulated Lateral Capacity: ...... 252 lbs

Choose Window Sill Plate Connections based on loads from Table 3.8 Three second gust wind speed (700 yr) and Exposure category: ...... 160 mph Exp. B Window Sill Plate Span: ...... 3 ft

Tabulated Lateral Connection Capacity - Each End of Window Sill: ...... 252 lbs

58 PRESCRIPTIVE DESIGN

Table 3.7 Header Connection Requirements for Wind (Dead Load Assumptions: Roof Assembly DL = 15 psf) Exposure B

700‐yr. Wind Speed 110 115 120 130 140 150 160 170 180 195 3‐ second gust (mph) Header Required Capacity of Connection at Each End of Header (lbs)1 Roof Span Span (ft) 2,3,4 2,3,4 2,3,4 2,3,4 2,3,4 2,3,4 2,3,4 2,3,4 2,3,4 2,3,4 (ft) U L U L U L U L U L U L U L U L U L U L 2 48 79 59 87 70 94 95 111 122 129 151 148 181 168 214 190 248 212 304 249 4 95 159 118 173 141 189 190 222 244 257 301 295 362 336 428 379 497 425 608 499 6 143 238 176 260 211 283 285 333 366 386 452 443 544 504 641 569 745 637 912 748 8 191 317 235 347 282 378 381 443 487 514 602 590 725 672 855 758 994 850 1216 998 10 238 397 294 434 352 472 476 554 609 643 753 738 906 839 1069 948 1242 1062 1520 1247 12 12 286 476 353 520 422 567 571 665 731 771 903 885 1087 1007 1283 1137 1491 1275 1824 1496 14 334 555 412 607 493 661 666 776 853 900 1054 1033 1268 1175 1497 1327 1739 1487 2128 1746 16 381 635 470 694 563 756 761 887 975 1028 1204 1181 1449 1343 1710 1516 1987 1700 2432 1995 18 429 714 529 781 634 850 856 998 1097 1157 1355 1328 1631 1511 1924 1706 2236 1912 2736 2244 20 477 794 588 867 704 944 951 1108 1218 1285 1505 1476 1812 1679 2138 1895 2484 2125 3041 2494 2 71 79 89 87 108 94 149 111 193 129 240 148 290 168 344 190 401 212 492 249 4 141 159 178 173 216 189 297 222 385 257 479 295 580 336 688 379 801 425 984 499 6 212 238 267 260 324 283 446 333 578 386 719 443 870 504 1031 569 1202 637 1476 748 8 283 317 356 347 432 378 595 443 770 514 959 590 1161 672 1375 758 1603 850 1968 998 10 353 397 445 434 540 472 744 554 963 643 1199 738 1451 839 1719 948 2003 1062 2460 1247 24 12 424 476 534 520 648 567 892 665 1156 771 1438 885 1741 1007 2063 1137 2404 1275 2953 1496 14 495 555 623 607 757 661 1041 776 1348 900 1678 1033 2031 1175 2406 1327 2805 1487 3445 1746 16 565 635 712 694 865 756 1190 887 1541 1028 1918 1181 2321 1343 2750 1516 3205 1700 3937 1995 18 636 714 801 781 973 850 1338 998 1733 1157 2158 1328 2611 1511 3094 1706 3606 1912 4429 2244 20 707 794 890 867 1081 944 1487 1108 1926 1285 2397 1476 2901 1679 3438 1895 4007 2125 4921 2494 2 94 79 120 87 146 94 203 111 264 129 330 148 400 168 475 190 555 212 682 249 4 189 159 240 173 293 189 406 222 529 257 660 295 801 336 950 379 1109 425 1364 499 6 283 238 360 260 439 283 609 333 793 386 990 443 1201 504 1426 569 1664 637 2046 748 8 377 317 479 347 586 378 813 443 1058 514 1321 590 1602 672 1901 758 2218 850 2728 998 36 10 472 397 599 434 732 472 1016 554 1322 643 1651 738 2002 839 2376 948 2773 1062 3411 1247 12 566 476 719 520 879 567 1219 665 1586 771 1981 885 2402 1007 2851 1137 3328 1275 4093 1496 14 660 555 839 607 1025 661 1422 776 1851 900 2311 1033 2803 1175 3327 1327 3882 1487 4775 1746 16 755 635 959 694 1172 756 1625 887 2115 1028 2641 1181 3203 1343 3802 1516 4437 1700 5457 1995 18 849 714 1079 781 1318 850 1828 998 2379 1157 2971 1328 3604 1511 4277 1706 4991 1912 6139 2244 20 943 794 1198 867 1465 944 2032 1108 2644 1285 3301 1476 4004 1679 4752 1895 5546 2125 6821 2494 U=Connector uplift load. L=Connector lateral load (perpendicular to the wall).

1 Tabulated lateral connection requirements shall be permitted to be multiplied by 0.75 and 0.92, respectively, for framing not located within 8 feet of building corners. 2 Tabulated connection requirements assume a roof assembly dead load of 9 psf (0.6 x 15 psf = 9 psf). 3 Tabulated uplift loads are specified for headers supporting a roof assembly. When calculating uplift loads for headers supporting floor loads, the tabulated uplift loads shall be permitted to be reduced by 36 plf times the header span for each full wall above. 4 For jack rafter uplift connections, use a roof span equal to twice the jack rafter length. The jack rafter length includes the overhang length and the jack span.

Wall Detailing Summary (cont’d)

Table W6.19 Header Detailing Requirements for Wind and Gravity Loads Ext. Non-loadbearing Ext. Loadbearing Header Span and Details Headers & Sill Plates Int. Loadbearing (1-1&1-2) (1-A&1-B) Type Dropped or Raised - - 20F Glulam Size/Plies - - 3-1/8x13-3/4 Uplift load 1312 - - 9' Lateral load 756 - - No. Jack studs 5 - - No. King studs 3 - - King to plate nails 2-16d comm. - - Type Dropped or Raised - Dropped or Raised 20F Glulam 20F Glulam Size/Plies - 3-1/8x9-5/8 3-1/8x9-5/8 Uplift load 1091 - n/a 6' Lateral load 504 - n/a No. Jack studs 3 - 4 No. King studs 2 - 1 King to plate nails 2-16d comm. - n/a Type - Dropped Dropped or Raised Size/Plies - 1-2x6 flat 2-2x10 Uplift load - n/a n/a 4' Lateral load - 336 n/a No. Jack studs - n/a 3 No. King studs - 2 1 King to plate nails - 2-16d comm. n/a Type Dropped or Raised Dropped - Size/Plies 2-2x8 1-2x6 flat - Uplift load 437 n/a - 3' Lateral load 252 252 - No. Jack studs 2 n/a - No. King studs 1 2 - King to plate nails 2-16d comm. 2-16d comm. -

60 Wall Detailing Summary (cont’d)

Table W6.20 Header Detailing Requirements for Gravity Loads Only Ext. Non-loadbearing Ext. Loadbearing Header Span and Details Headers & Sill Plates Int. Loadbearing (1-1 & 1-2) (1-A & 1-B) Type Dropped or Raised - - 20F Glulam Size/Plies - - 9' 3-1/8x13-3/4 No. Jack studs 5 - - No. King studs 1 - - Type Dropped or Raised Dropped or Raised - 20F Glulam Size/Plies 1-2x6 flat - 6' 3-1/8x9-5/8 No. Jack studs 3 n/a - No. King studs 1 1 - Type - Dropped or Raised Dropped or Raised Size/Plies - 1-2x6 flat 2-2x10 4' No. Jack studs - n/a 3 No. King studs - 1 1 Type Dropped or Raised Dropped or Raised - Size/Plies 2-2x8 1-2x6 flat - 3' No. Jack studs 2 n/a - No. King studs 1 1 -

61 Polling Question 5) Which of the following is false regarding dropped headers? a) Requires a lateral wind load check b) Assumes full lateral buckling restraint c) Spans less than a comparable raised header d) None of the above

This concludes the American Institute of Architects Continuing Education Systems Course

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