Wood Connections Ii

WOOD CONNECTIONS II

Michelle Kam-Biron, S.E. Wood Products Council – WoodWorks!

Continuing Education

Wood Products Council is a Registered Provider with The American Institute of Architects Continuing Education Systems. Credit earned on completion of this program will be reported to CES Records for AIA members. Certificates of Completion for non‐AIA members are available on request.

This program is registered with the AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presen‐ tation.

1 Learning Objectives

Basic Theory Design Examples Resources Available

Mechanical Connectors

Common Fasteners • Nails • Staples • Wood Screws • Metal plate connectors • Lag screws • Bolts

Mechanical Connectors

Other types: •Rivets • Split rings • Shear plates • Wood dowels

2 Mechanical Connectors

Codes, Provisions, and Guidance

Prescriptive Engineered – Follows a recipe – NDS & NER-272 – CBC, ER, NER reports – Design values – No design values – Accounts for performance of different materials – Nominal value • End use application

Codes, Provisions, and Guidance

ICC Reports NER-272 International Staple, Nail and Tool Association ESR-1539 International Staple, Nail and Tool Association ISANTA

3 Codes, Provisions, and Guidance

CBC & ICC-ES

Codes, Provisions, and Guidance

National Design Specification for Wood Construction, 2005 Edition (NDS)

Where to Find Specifics

The NDS has design provisions

Allowable = nominal x adjustment factors

Adjustment factors account for a wide range of different end use applications

4 Basic Theory: Engineered Design

Nominal Design Values defined by a table in code or NDS. Nominal Design Values based on equations in the NDS NilNominal DDiesign VVlalues bbdased on assumed end‐use conditions –Normal Load Duration (10 year) –Dry Condition of Use –No Sustained exposure to elevated temperatures –And others.

Basic Theory: Engineered Design

For nails, spikes, bolts, lag screws and wood screws – Lateral load design values are calculated by yield‐limit equations – Yield Model – Withdrawal design cappyacity calculated from empirical (test‐based) equations. Split rings, shear plates, dowels, drift pins, and timber rivets etc. – Lateral and withdrawal design values from empirically based tables.

Connection Behavior

Strength Ductility

5 Mechanical Connections

Basic Type of Connections Dowel-type fasteners Bolts, Lag Screws, Wood Screws, Nails/Spikes, Drift bolts, and Drift Pins Split Ring and Shear Plate Connectors Timber Rivets Lateral and Withdrawal Loads.

NDS DOWEL YIELD EQUATIONS

MODE I – bearing- dominated yield of wood fibers MODE II – pitifivoting of fastener with localized crushing of wood fibers

NDS DOWEL YIELD EQUATIONS

MODE III – fastener yield in bending at one plastic hinge and bearing –dominated yield of wood fibers MODE IV – fastener yield in bending at two plastic hinges and bearing –dominated yield of wood fibers

6 NDS DOWEL YIELD EQUATIONS

•4 Modes

•6 Equations

•Sing le & Double shear

•Reduction term Rd

NDS DOWEL YIELD EQUATIONS

7 NDS DOWEL YIELD EQUATIONS

Fastener Values

NER’s are now called: ESR ES ICC Evaluation Service Reports

Connecting Wood

Wood Bearing Strength Sawn wood Glulam OSB Plywood Structural Composite Lumber (SCL)

8 Making Angle to Grain Adjustments

Calculate wood bearing strength, Fe, at any angle to grain (for fastener dia. > 0.25”) Hankinson Formula F Fe⊥ F = e eθ F sin 2 θ + F cos2 θ θ Feθ e e⊥

Fe⊥

Fell

The Basics ‐ Engineered

Lateral connection strength, Z, depends on: Crushing (bearing) strength of wood Size of wood pieces Fastener size and strength Plus appropriate end use Z adjustment factors ¾i.e. Wet service, edge distance, end grain, etc.

Nails Nail capacity tables in 2005 NDS

9 Fastener Interchangeability

NER‐272 & ESR‐1539

Has “conversion” tables for prescriptive requirements For example, if model code requires 8d commons at 6” oc, then what fastener type and spacing is “equivalent” Has values for engineered designs for staples and a variety of other power‐driven fasteners Available from international staple, nail and tool association (ISANTA) www.isanta.org 708‐482‐8138

Mechanical Connections

Nail installation Overdriving reduces performance

Mechanical Connections

Overdriven nails TT‐012A

APA Recommendations –Prescriptive

If < 20% fasteners overdriven by <1/8”, then they may be ignored.

If > 20% fasteners overdriven by >1/8”, then add 1 additional fastener for every 2 overdriven.

10 CAUTION!

If the additional nails violate the minimum spacing requirements (3” o.c. for 2 inch lumber for splitting), use staples and ignore the original nails.

Mechanical Connections

Overdriven nails

APA Recommendations – Mechanics Based If < 20% fasteners overdriven by <1/8”, then they may be ignored. Otherwise, re‐analyze capacity based on average thickness of panel measured from the bottom of the nail head. (i.e. 5/8” panel with fasteners overdriven by 1/8” = capacity of ½” panel.) ‐ Adjust nailing schedule accordingly.

The Basics - Engineered

Withdrawal Connection Strength Depends On: Depth of penetration Wood density Fastener size and type Plus appropriate end use adjustment factors i.e. wet service, edge distance, end grain, etc.

11 Fastener Penetration

Lag screws, wood screws, and nails

Minimum Fastener Type Full reduced Tip Per 11.1 Lag Screws 8D 4D Excluded 6D Wood Screws 10D Included (inc. from 4D) Nails & Spikes 10D 6D Included

D = Diameter (in) If min. < p < full then Z x p/full per table footnotes.

Lag Screws

Full Body Diameter

Lag Screws

All tabulated values in the 2005 NDS are

based on Dr

12 Lag Screws

For calculations using the shank diameter, D

DOWEL BEARING STRENGTHS

Table 11.3.2 SAWN LUMBER

DOWEL BEARING STRENGTHS

ENGINEERED WOOD TABLE 11.3.2B PRODUCTS

Glulam is a function of the species used. LVL and other SCL see manufacturer.

13 Nominal Design Values

Tabulated Values in NDS

They must be adjusted to account for actual conditions. Examples for dowel type fasteners:

CD = Load duration factor (Only ASD Basic Load Combination) CM = Wet service factor Ct = Temperature Factor Cg = Group action factor, C∆ = Geometry factor

Ceg = End grain factor Cdi = Diaphragm Factor Ctn = Toe‐nail factor KF = Format conversion Factor, Appendix N.3.1 (Only LRFD) Φz =Resistance Factor (Only LRFD) λ = Time effect factor, Appendix N.3.3 (Only LRFD)

CD, Load Duration Factor ASD ONLY TABLE 2.3.2 Wood capacity greater for short time loading LOAD DURATION Load Duration Factor - Typical Loads CD Permanent 0.9 Dead Load

Ten years 1.0 Floor live load

Two months 1151.15 Snow load

Seven days 1.25 Construction load Ten minutes 1.6 Wind/Earthquake

Impact (does not 2.0 Vehicles apply to connections) These factors are applied to member capacity

14 CM, Wet Service Factor

Design Values Wood seasoned to a moisture content of 19% Continuously dry conditions (most covered structures) CM apply to: Wood unseasoned or partially seasoned or Exposed to wet service use Shall not apply for nails in withdrawal

2005 NDS Provisions

Wet Service Factor, CM for connection Z values

Saturated Bolts Lag screws Wood screws 19% MC

fabrication MC in-service MC

Dry CM 1.0 0.7 0.4 Lateral Load 1.0 0.7 1.0 Withdrawl Load (lag & wood screws only)

2005 NDS Provisions

Wet Service Factor, CM for connection Z values Bolts Lag screws CM = 0.7 if D < ¼” Wood screws Saturated CM = 1.0 if: 1 fastener 19% MC

2+ fastener

Dry C 0.4 Lateral Load M Split splice plates fabrication MC in-service MC Table 10.3.3 footnote 3

15 Ct, Temperature Factor

Ct apply to: Sustained exposure to elevated temperatures up to 150 degree Fahrenheit

Mechanical Connections

Larger fasteners

Group action factor, Cg – NDS tables – Equation calculation Does NOT app ly t o sill plates – Unit loads act along the length of the member – Loads are not axial

Mechanical Connections

Figure 10B

16 Calculated – Group Action Factor, Cg

EQ. 10.3-1

Applicable for split ring connectors, shear plates connectors, or dowel-type fasteners with D < 1” in a row.

Calculated – Group Action Factor, Cg

10.3.6

Calculated – Group Action Factor, Cg

Example:

Find Cg for two rows of 1” diameter bolts spaced 4” apart in a wood- to-wood double shear splice connection using 2x12’s for main and side members.

17 Calculated – Group Action Factor, Cg

EQ. 10.3-1

m = 0.808

u = 1.023

REA = min (EsAs/EmAm, EmAm/EsAs) = 0.5

Cg = 0.669

Tabulated – Group Action Factor, Cg

• As/Am> 1.0, so use Am /As =0.5 to enter column 1 of the table (footnote 1)

• Use Am for column 2 (footnote 1) • Read across to column for 10 fasteners in a row

• Interpolate Cg = 0.665

Tabulated – Group Action Factor, Cg

Am= gross x-sectional As = sum of gross x- area of main sectional areas of all member, in2 side members, in2

Table 10.3.6C

18 Geometry Factor, C∆

Bolts ‐ Spacing, End, & Edge Distances Parallel and perpendicular to grain Figure 11G Tables 11.5.1A through D When D < ¼” CΔ = 1.0 When D > ¼” If end distance OR spacing < required, then CΔ min. applied to all bolts

Local Stress in Fastener Group

10.1.2 Stresses in Members at Connections “Local stresses in connections using multiple fasteners shall be checked in accordithiilfiidance with principles of engineering mechanics. One method for determining these stresses is provided in Appendix E.”

Local Stress in Fastener Group

Closely spaced fasteners •Brittle failure •Lower capacity

Wood failure mechanism need to be consider in design U

19 Local Stress in Fastener Group

Properly spaced fasteners •Increased ductility •Higher capacity

Spread out the fasteners!

Local Stresses in Fastener Groups

Appendix E NDS Expressions

Local Stresses in Fastener Groups

Appendix E NDS Expressions

Group tear-out:

20 Geometry Factor, C∆

Lag Screw - Spacing, End, & Edge Distances 11.1.3.7 Shall not be less than the requirements for bolts Tables 11.5.1A through D plus E. Wood Screw, Nails and Spikes - Spacing, End, & Edge Distances 11147&11156Shallbesufficienttopreventsplittingof11.1.4.7 & 11.1.5.6 Shall be sufficient to prevent splitting of the wood. Drift Bolts and Drift Pins - Spacing, End, & Edge Distances 11.1.6.3 Shall not be less than the requirements for bolts Tables 11.5.1A through D.

Geometry Factor, C∆

Split Ring and Plate Connectors - Spacing, End, & Edge Distances Placement of Split Ring and Plate Connectors per 12.3 Geometry Factors , C∆ Table 12. 3 Timber Rivet - Spacing, End, & Edge Distances Placement of Timber Rivets per 13.3 Geometry Factors, C∆ Table 13.2.2B

Tabulated Values in NDS

Cd = Penetration Depth Factor Split ring and Shear Plate. See Tables12.2.3

Ceg = End grain factor (Not recommended) Dowel‐type fasteners and Lag Screws Ch. 11.5.2

Cst = Metal Side Plate Factor Shear Plate –Table 12.2.4 (depends on Species group) Timber Rivets –Table 13.2.3 (depends on thickness of metal side plate) Is only applied when rivet capacity controls.

Cdi = Diaphragm Factor Applies to nails or spikes used in diaphragms

Lateral design values, Z x Cdi = 1.1

21 Toe-nail Factor, Ctn

Nail installation (11.5.4) Correct toe nailing Fig. 11A

Ctn = 0 . 67 for withdrawal

Ctn = 0..83 for lateral

"Air Nail" Factor, Cair

Cair= 0.00

Summary of Connection Design

Two General Approaches: Prescriptive CBC, NER and ER Engineered NDS and NER-272 Nominal strength calculated Adjusted by for application, end-use adjustment factors

22 Design Example 1

Nail Tension Tie Strap Design connection ties between first and second floor. Given: 9-1/2” I-joist floor framing 9-1/2” 2x6, dry Douglas Fir-Larch studs spaced at 16”o.c. 2400 lbs. tension (overturning wind)

2x6 Dbl. Studs

3”

Design Example 1

Nail Tension Tie Strap = Side member 2‐2x6 = Main member

Fe=61850 psi

Table 11P Table 11.3.2 Minimum Penetration for full values = 10D = 10x.148 = 1.5” Since penetration = 3”‐.06” > 1.5” OK Note: If 6D < p < 10D then Z = Z x (p/10D) Table 11.3.1B

Design Example 1 Nail Tension Tie

Mode IIIs controls: Table 11.3.1A

EQ. 11.3‐5

23 Design Example 1

Nail Tension Tie ASD

Z’ = Z x CD x CM× Ct Z’ = 0.116 x 1601.60 X 110.0 x 101.0 = .186 n = 2.4 kips/.186 kips = 12.9 nails

Use: 14 – 10d common nails per side, or 2 rows of 7 each.

(Note: CD can not be used for Alternative Load Combinations)

Design Example 1

Nail Tension Tie LRFD

Appendix N Table N1, N2 & N3

Design Example 1

Strap = Side member Nail Tension Tie 2‐2x6 = Main member Table 11P

Fe=61850 psi

Minimum Penetration for full values = 10D = 10x.148 = 1.5” Since penetration = 3”‐.06” > 1.5” OK Note: If 6D < p < 10D then Z = Z x (p/10D)

24 Design Example 1

Nail Tension Tie

Strap = Side member 2‐2x6 = Main member Table 11P

Side Member thickness, ts = 18ga Nail Diameter, D = 0.148” G=0.50 Douglas Fir‐Larch (Table 11.3.2A)

Z = 115 lbs.

Design Example 1

Nail Tension Tie 2005 NDS Table 11P notes & Table 10.3.1

Design Example 1 Nail Tension Tie

25 Design Example 1 Nail Tension Tie

Design Example 1 Nail Tension Tie

Design Example 2 Group Fasteners Loaded Parallel to Grain

Determine the group action factor for the bolted butt joint shown.

26 Design Example 2 Group Fasteners Loaded Parallel to Grain Solution: An effective area for the 3 x 6 in. member is: 2 Am = 2.5 × 5.5 = 13.75 in.

2 As = 2 × (1.5 x 5.5) = 16.50 in. for 2 - 2 x 6’s

Per footnote 1 of Table 10.3.6A

As/Am > 1 ׵ use Am/As = 13.75/16.5 = 0.833 and use Am in place of As

Design Example 2 Group Fasteners Loaded Parallel to Grain

Group reduction:

Linear int er pol ati on:

Cg = 0.87 + (0.93 – 0.87) × ((0.833 – 0.5)/(1– 0.5)) = 0.91

Cg = 0.91

Design Example 3

Group Fasteners Loaded Perpendicular to Grain Determine the group action factor for the bolted connection shown.

27 Design Example 3 Group Fasteners Loaded Perpendicular to Grain Solution: An effective area for the 4 x 12 in. member is: 2 Am = 2.5 × 2 x 3.5 = 17.5 in. Where 2.5 x 2 = overall width of fastener group and 3.5 is the thickness of the main member.

2 As = 2 × (2.5 x 7.25) = 36.25 in. for 2 - 3 x 8’s

Per footnote 1 of Table 10.3.6A

As/Am > 1 ׵ use Am/As = 17.5/36.25 = 0.48 (round to 0.5 for simplicity) and use Am in place of As

Design Example 3 Group Fasteners Loaded Perpendicular to Grain

Group reduction:

Linear int er pol ati on:

Cg = 0.95 – (20 – 17.5) × ((0.95 – 0.92)/(20– 12)) = 0.94

Cg = 0.94

Design Example 4 Bolted Splice Joint Check

Determine the size, number, and placement of bolts needed to transfer the 7500 lb. load (dead load plus snow load) through the butt joint shown. Wood is seasoned No. 1 Douglas-fir (MC < 19%), which will remain dry in service (MC < 19%).

28 Design Example 4 Bolted Splice Joint Check Size of member:

Assuming a nominal 2 × 8 is used, 1.2 is the size factor (Table 4a)

CD = 115(S1.15 (Snow Loa dTd Ta ble 232)2.3.2)

2 A (required) = P/Ft = 7500/(675 × 1.15 × 1.2*) = 8.05 in.

Try a 2 × 8 in., A = 10.875 in.2 for both main member and side plates

Design Example 4 Bolted Splice Joint Check Bolts:

Try 5/8-in. bolts

Z (()nominal) = 1310 lb. p(per bolt (Table 11F )

Z’ (allowable) = Z × CD ×CM Z’ = 1310 × 1.15 × 1.0 = 1506 lb.

Number required = 7500/1506 = 4.98

Try 6 - 5/8 in. bolts, two rows of (3) bolts.

Design Example 4 Bolted Splice Joint Check

Group reduction:

2 Am = 1.5 × 7.25 = 10.875 in.

2 As = 2 × 10.875 = 21.75 in.

Per footnote 1 of Table 10.3.6A

As/Am > 1 ׵ use Am/As = 10.875/21.75 = 0.5 and use Am in place of As

29 Design Example 4 Bolted Splice Joint Check Group reduction:

Linear interpolation:

Cg = 0.96 – (12 – 10.875) × ((0.96 – 0.92))(/(12– 5)) = 0.95

Q = 1506 × 0.95 × 6 = 8584 lb. > 7500 lb. ׵ ok

Design Example 5 Multiple-Bolt Tension Connection Determine the adjusted ASD capacity of the multiple-bolt double shear tension connection at the end of the 24F-V4 Douglas-Fir glulam member (24F-1.8E Stress Class): Given: – (2) ¼” thick A36 steel side plates 5 1/8 x 12 GLB – (6) 1” Φ A307 bolts GLB dry (initial & service) – Seismic Tension Load Temperature normal

2 steel pl’s 5 1/8 x 12 glulam (1/4”x6”) 8” 4” 4”

T T 3” 6” 3” 6”

1”Φ bolts typ. 1”Φ bolts typ.

Design Example 5 Multiple-Bolt Tension Connection GIVEN: D = 1.0 in. ts = 0.25 in F = 1.5F =1.5(58000) Fyb = 45 ksi es u = 87,000 psi (A36 steel plate) tm = 5.125 in. θm = 0 degrees

Gm = 0.50 Fem = 5600 psi

From table 11I Z║ = 5720 lbs.

Adjusted ASD connection capacity based on bolt yield limit equations: n = 3 bolts in each row

CD = 1.6 (seismic) CM = 1.0 given Ct = 1.0 given

30 Design Example 5 Multiple-Bolt Tension Connection

Find Group Action Factor Cg 10.3.6:

EQ. 10.3-1

γ = 270,000(D1.5) load/slip modulus = 270,000(11.5)= 270,000 lb/in. m = 0.0.8601

u = 1.011

REA = min (EsAs/EmAm, EmAm/EsAs) = 0.8321

Cg = 0.993

Design Example 5 Multiple-Bolt Tension Connection

Find Group Action Factor Cg 10.3.6:

Or using table 10.3.6C

As/Am (3/61.5) = 0.05

Cg = 0.993

Design Example 5 Multiple-Bolt Tension Connection

Find GroupGeometry Action Factor C∆ 11.5.1: Check spacing and edge distance requirements:

End distancemin = 7D = 7(1”) = 7 in. < 8 in. OK (for C∆ = 1.0 parallel tension member table 11.5.1B) c.-to-c. spacing between bolts in a row s = 4D OK

(for C∆ =10table1151C)= 1.0 table 11.5.1C) s = 4(4”) = 4 in.< 4 in. OK Spacing between rows = 1.5D (table 11.5.1D) =1.5(1”) = 1.5 in. < 3 in. OK Edge distance = 1.5D (for lm/D = 5.125/1 = 5.125 < 6 table 11.5.1A) = 1.5(1”) = 1.5 in. < 1.5

C∆ = 1.0 (since all NDS base dimensions are met or exceeded)

31 Design Example 5 Multiple-Bolt Tension Connection

Adj P = N(Z’) = N(Z)(CDCMCtCgC∆) = (6)(5720)(1.6)(1.0)(1.0)(0.993)(1.0) = 54,500 lb

Design Example 5 Multiple-Bolt Tension Connection

Check local stresses:

Adjusted ASD capacity based on tension and shear stresses in the glulam member:

Since the bolts penetrate the wide face of the 24F-V4 glulam member the shear design value for bending about the strong x-axis. multiply by a reduction factor 0.72 (footnote 4 supplement table 5A).

Fv = (0.72)(265psi) = 191 psi

F’v = Fv(CDCMCt)= 191(1.6)(1.0)(1.0) = 305 psi

F’t = Ft(CDCMCt)= 1100(1.6)(1.0)(1.0) = 1760 psi

Design Example 5 Multiple-Bolt Tension Connection Net section tension for ASD (NDS eq. E.2-1): An = 5.125[12-2(1.0+1/16)] = 50.6 in.2 (Note: 1/16” was added to the bolt to account for drilling oversize holes in accordance with NDS 11.1.2)

Z’NT = F’t(An) = 1760(50.6) = 89100 lb > 54,500 lb OK

5 1/8” 5 1/8” Net section of Portion of net glulam area between rows of bolts 12” 12” Bolt Holes

32 Design Example 5 Multiple-Bolt Tension Connection Row tear-out for ASD (NDS Eqs. E.3-2 and E.3-3):

scrit = s = 4.0 in Z’RT-1 = Z’RT-2 = nFv’t scrit = 3(305)(5.125)(4.0) = 18775 lb

nrow Z’RT = ∑Z’RT-2 = 18,775 + 18,775 =37,500 lb. < 54,000 lb. i=1 Group tear-out for ASD (NDS Eqs. E.4-1):

Agroup-net = 5.125[3-2(1/2)(1.0+1/16)] = 9.93 in. Z’GT = (Z’RT-1)/2 + (Z’RT-2)/2 + F’tAgroup-net Z’GT = 18,775.2 + 18,775/2 + 1760(9.93) = 36,300 lb < 54,500 lb The adjusted ASD capacity is 36,000 lb due to group tear-out at the connection

RESOURCES

Where to get more information

WEBSITES

American Wood Council ‐ www.awc.org APA –The Engineered Wood ‐ www.apawood.org Canadian Wood Council ‐ www.cwc.ca Forest Products Laboratory ‐ www.fpl.fs.fed.us Southern Pine Council ‐ www.southernpine.com Wood Truss Council of America – www.woodtruss.com WoodWorks ‐ www.woodworks.org

33 Where to Find Specifics

CBC & ICC-ES

Where to Find Specifics

NDS

Where to Find Design Examples

NDS Free Download htttp://www.awc.org

34 Where to Find Design Examples

NDS Free Download htttp://www.awc.org

Where to Find Design Examples

Timber Rivet Connections

AWC & WWPA

FREE DOWNLOAD Notching & Boring Guide http://www2.wwpa.org/TECHGUIDEPAGES/Literature/tabid /883/Default.aspx Timber Rivet Connections •www.awc.org/pdf/TimberRivetConnections.pdf Lag Screw Connections •www.awc.org/pdf/DA1-LagScrew.pdf Dowel Equations for Lateral Loads 2001 NDS •www.awc.org/pdf/tr12.pdf Toenail Connections •www.awc.org/pdf/DA2-Toenails.pdf Post Frame Ring Shank Nails Connections •www.awc.org/pdf/DA4-RingShank.pdf

35 For More Information: APA Forms

Go to www.apawood.org and enter the Publications store The following publications expand on the information given in this presentation and can be downloaded for free using subject, title, or form number

APA Forms (www.apawood.org)

T300 – Glulam connection details E830 – Screw and plywood connections E825 - Bolt and plywood connections D485 – Corrosion resistant fasteners TT-035 – Corrosion resistant fasteners TT-036 – Glued floors TT-039 – Nail withdrawal TT-070 – Nail pull through

Next...

Design software

36 WWPA Free Downloadable

WWPA Lumber Design Suite Beams and Joists Post and Studs Wood to Wood Shear Connections (nails, bolts, wood screws and lag screws)

http://www2.wwpa.org/TECHGUIDEPAGES/DesignSoftware/tabi d/859/Default.aspx

AWC Free Online Calculator

Single and Double Shear Withdrawal • Bolts, nails, lag screws and wood screws. Wood-to-Wood Wood-to-Concrete Wood-to-Steel

http://awc.org/calculators/connections/ccstyle.asp

www.APACAD.org

37 www.WoodUniversity.org

AWC Free Online Course

http://www.awc.org/HelpOutreach/eCourses/index.html

AWC Free Online Course

http://www.awc.org/HelpOutreach/eCourses/STD104/STD104eCo urseV11-2007.pdf

38 Take home messages...

It’s easy to create strong durable wood connections 1. Avoid the use of details which induce tension perpendicular to grain stresses in the wood 2. Allow for dimensional changes in the wood due to potential in-service moisture cycling 3. Minimize exposure of end grain 4. Avoid moisture entrapment in connections 5. Use smaller multiple fastener connections 6. Multiple resource available to assist

Quiz: Is the below a code‐conforming connection?

Questions???

WoodWorks! Michelle Kam-Biron, S.E. 805.498.4864 [email protected] www.woodworks.org