Mass Timber – the Next Generation of Wood Construction

Mass Timber – The Next Generation of Wood Construction

Tom Williamson, P.E. Timber Engineering LLC Disclaimer: This presentation was developed by a third party and is not funded by WoodWorks or the Softwood Lumber Board.

Course Description

This presentation provides an overview of two products at the heart of the modern mass timber revolution: glued- laminated timber (glulam) and cross-laminated timber (CLT). Advantages and unique design considerations associated with these products will be covered, including specification, code compliance, connections, fire resistance and structural design. Modern glulam and CLT applications in North America will be reviewed using project examples. The potential for expanded applications, including larger and taller mass timber buildings, will also be highlighted in the context of current research, testing, and code and standard development processes. Learning Objectives

1. Become familiar with mass timber building products including cross-laminated timber and glued-laminated timber.

2. Review proper selection and specification of CLT in the context of relevant industry standards and building codes.

3. Demonstrate the fire-resistive characteristics of glulam and CLT as it pertains to their use as exposed structural framing members in mass timber construction.

4. Discuss the breadth of resources available to designers in North America to aid in mass timber design. Optional Wood Building Systems

Wood Building Systems

Timber Post and Light (stick) Mass Frame Beam Frame Timber

5 Mass Timber Construction

Nail Laminated Timber Glued Laminated Timber Panels (NLT) Panels (GLT)

GLT Beams and Columns

Structural Composite Cross Laminated Lumber Panels (SCL) Timber Panels (CLT) CLT and Glulam are Environmentally Friendly - Sustainable and Green

Produced from small dimension lumber harvested from managed and sustainable forests Timber resource utilization optimized using a wide range of lumber grades and a wide variety of species

Act as carbon sinks and store CO2 Manufacturing involves low energy energy use processes Excellent LCA profiles: emitting less greenhouse gases, less air pollutants, less water pollution, less solid waste, and utilizing less natural resources than competing materials Glulam & CLT = Green Glulam – One of the Original Glued Engineered Wood Composites

Over 120 years of use worldwide Continues as a major structural material Original U.S. Glulam Structure USDA Forest Products Laboratory

2009 Over 75 years of 1934 in-service use Matching Lumber Quality to Induced In-Service Stresses Large Cross Sections Are Possible

21” x 27” x 110’ Note multiple pieces positioned side by side

Any gaps in the face laminations are limited to ¼ inch Long Span Beams with Spans of 100 feet or greater Virtually Unlimited Versatility of Shapes and Spans Natural Aesthetics of Wood Glulam Manufacturing Standard ANSI A190.1-2017 § Specifies product qualification and quality assurance requirements § Third-party inspection by an approved agency is required on an on-going basis § Building codes require that all glulam must bear a grademark meeting APA/ANSI A190.1 Quality Grademarks

APA UNBALANCED ARCH 24F-V3 APA Y117 SP PLANT 0000 ANSI A190.1-2012 Glulam Adhesive Specifications

Adhesives used for glulam must meet ANSI 405 Standard for Adhesives for Use in Structural Glued Laminated Timber Basic Glulam Design Concepts

§ Type of member / load application § Determination of allowable design stresses / layup selection § Stress modification factors § Structural analysis § Special design provisions § Connection design /detailing Member Type

Column Truss member

Simple span beam Cantilever span beam Curved beam / arch Glulam Lay-Ups 24F – 1.8E Bending Members

302-24 T.L. No. 2D No. 1 Tension No. 2 Compression Zone Zone No. 2 No. 2

Inner Zone No. 3 No. 3 Inner Zone

No. 2 No. 2 No. 1 Tension No. 1 Tension Zone 302-24 T.L. 302-24 T.L. Zone Balanced Unbalanced Full Scale Glulam Beam Tests

The U.S. has one of the largest combined full scale glulam beam databases in the world

One predictable result is the failure in a bending member test will always occur in the tension zone

Thus, the importance of using high quality tension lams introduced in 1971 Single Grade Glulam Layup

§ Same lumber grade and species used throughout § Primarily for use in axially loaded members, such as columns and truss chords Loading Orientation

Typical use Typical use for Y for beams X-X panels Y-Y major major axis axis X X X Y Y

Y Fbx ≠ Fby Ex ≠ Ey Fvx ≠ Fvy Fc⊥x ≠ Fc⊥y Basic Glulam Design Concepts

§ Design values are derived in accordance with: Sources of Design Properties NDS Supplement 1. Sawn Lumber Grading Agencies 2. Species Combinations 3. Section Properties 4. Design Values • Lumber and Timber • Non-North American Sawn Lumber • Structural Glued Laminated Timber • MSR and MEL NDS Supplement Stress Classes Glulam Design Stresses

§ Conventional glulam beams are rated at: 6 Fb = 2,400 psi E = 1.8 x 10 psi § Higher design stresses also available: Southern Pine 6 Fb = 3,000 psi E = 2.1 x10 psi LVL hybrid 6 Fb = 3,000 psi E = 2.1 x10 psi

See Product Reports on APA web site for manufacturers who produce the 30 F-2.1E layups E-Rated Southern Pine Layup 30F – 2.1E Stress Grade

302-30 2.3E No. 1D 2.3E No. 1D 2.0E Design values published in ANSI 117 and APA No. 2M ICC-ES Report 1940

No. 1D 2.0E No. 1D 2.3E 302-30 2.3E LVL Hybrid Glulam with LVL Outer Laminations

§ Full length with no LVL Laminations finger joints required § LVL has greater tensile strength compared to lumber § 30F-2.1E stress level achieved § Design values in APA ICC-ES Report 1940 Sources of Design Values Industry Standards / ICC Codes § AWC NDS

§ ANSI 117 Design Specification

§ APA ICC-ESR Code Report 1940

§ Glulam standards are referenced in the IBC and IRC codes Basic Glulam Design Concepts

Fb’ = Fb CD CM Ct (CL or CV) CC

Fv’ = Fv CD CM Ct

E’ = E CM Ct

• CD = load duration factor

• CM = wet-use factor (16% or greater)

• Ct = temperature factor

• CL = beam stability factor

• CV = volume effect factor

• CC = curvature factor Curvature Factor for Bending Strength 2 CC = 1- 2000 (t/R) t = thickness of lamination (in) R = radius of curvature of the lamination (in)

Rrec = 27’- 6” for all species with t = 1.5” Rrec = 9’- 4” for Western species with t = 0.75” Rrec = 7’- 0” for Southern pine with t = 0.75”

Tighter radius can be achieved by using thinner laminations but t/R cannot exceed 1/100 for S.P and 1/125 for other softwood species Volume Factor for Bending Strength

1/x 1/x 1/x 21 12 5.125 C = ≤ 1.0 v L d b

L = beam length (ft) d = beam depth (inches) b = beam width (inches) x = 20 for Southern pine x = 10 for all other species Impact of Volume Effect Factor

Size: 8-3/4” x 72” x 100’

Cv = 0.82 for S.P. Cv = 0.68 for other species Fb’ = 2400 x .68 = 1632 psi for DF Basic Glulam Design Concepts

1 General Requirements for Building Design 2 Design Values for Structural Members 3 Design Provisions and Equations 4 Sawn Lumber 5 Structural Glued Laminated Timber 6 Round Timber Poles and Piles 7 Prefabricated Wood I-Joists 8 Structural Composite Lumber 9 Wood Structural Panels 10 Mechanical Connections 11 Dowel-Type Fasteners 12 Split Ring and Shear Plate Connectors 13 Timber Rivets 14 Shear Walls and Diaphragms 15 Special Loading Conditions 16 Fire Design of Wood Members Glulam Design: NDS

Includes both Allowable Stress Design (ASD) and Load and Resistance Factor Design (LRFD)

Significant changes to Glulam Chapter in 2012 and 2015 NDS LRFD vs. ASD

LRFD and ASD presentation formats are different Example equations for bending moment: Simple span beam with uniform load

ASD LRFD Applied stress ≤ Allowable stress Factored Load ≤ Factored fb ≤ Fb’ Resistance

M / Sx ≤ FbCD Mu ≤ Mn’

Mu ≤ Fb KF λ φ Sx

End result will be approximately the same member size for glulam Additional Glulam Design References

AITC “Timber Construction Manual”

McGraw-Hill “APA Engineered Wood Handbook”

McGraw-Hill “Wood Engineering and Construction Handbook” Basic Glulam Design Concepts

Unbalanced Layup High Strength Outer Compression Lams Medium Grade Inner Compression Lam

Lower Grade Inner Lams

Medium Grade Inner Compression Lam High Strength Outer Tension Lams Trademark and “TOP” Stamp for Unbalanced Layup

Trademark Improper Installation Unbalanced Layups “Upside Down” Bending Stresses

Based on full-size beam tests conducted at APA, the “upside down” bending stress is 75% of the normal bending capacity Specifying Camber

§ Glulam can be manufactured with camber to offset the anticipated dead load deflection § Very important for long span members Specifying Camber

Camber can be specified in inches or as a radius of curvature (R) Importance of Camber

12-1/4” x 84” 140 ft. clear span Camber = 8”

Spans of 80-100 feet or more are common for glulam Basic Glulam Design Concepts

The NDS design provides nominal lateral and withdrawal values for dowel type connectors (nails, screws, bolts) and specialty connectors such as shear plates, split rings and timber rivets Allowable = nominal x adjustment factors Adjustment factors account for a wide range of different end use applications All applicable to glulam Autzen Field University of Oregon

170 ft span cantilever beam Chicago Bears Walter Payton Practice Facility Moment splice 2010 Olympic Skating Oval Richmond, B.C. Terminal Two Raleigh Durham Airport Cathedral of Light Oakland, CA

Glass oculus weighs 24 tons LeMay America’s Car Museum Tacoma, WA EWP Manufacturing Plant Riddle, OR ERB Memorial Union Eugene, OR USDA Centennial Research Center Madison, WI Bullitt Center Seattle, WA Additional Glulam Information

www.apawood.org Glulam Product Guide Case Studies Technical Notes Beam and Column Tables Manufacturer Product Reports And much more Mass Timber Construction

Nail Laminated Timber Glued Laminated Timber Panels (NLT) Panels (GLT)

Glulam Beams and Columns

Structural Composite Cross Laminated Lumber Panels (SCL) Timber Panels (CLT) What is Cross Laminated Timber (CLT)

A new, to North America, glued engineered wood composite product that is massive and uses all lumber or SCL components, mostly lower grade

A wood product that has been used in Europe for more than 20 years and may be the key to breaking through conventional limitations on wood-framed construction, such as the building height limit

An exciting new engineered wood product that is energizing engineers and architects

Often referred to as “plywood on steroids” History of Cross Laminated Timber (CLT) §1993: 3-story CLT condominums built in Bavaria §1995 – 2000: CLT starts to be a competitor to established stickframe construction in Europe §2004: CLT moves into the commercial market with projects such as hotels and schools §2009: nine story CLT condominium structure erected in London §2010: ten story CLT structure erected in Melbourne Australia §2012 : CLT introduced into North America through adoption of PRG 320 §2015 : CLT recognized in 2015 NDS and 2015 IBC North American CLT Definition

A prefabricated solid engineered wood panel made of at least three orthogonally bonded layers of solid-sawn lumber or structural composite lumber (SCL) that are laminated by gluing of longitudinal and transverse layers with structural adhesives to form a solid rectangular- shaped, straight, and plane timber. CLT Plies and Layers

Alternate plies and layers CLT Cross Section Examples of CLT Configurations

3-ply 3-layer 5-ply 3-layer

5-ply 5-layer 7-ply 5-layer

6-ply 5-layer 8-ply 5-layer

9-ply 9-layer 9-ply 7-layer Typical CLT Dimensions

Length: 8 ft up to 40 ft or more (> 20‘ is common) Width: 4 ft up to 12 ft (8 ft is common) Thickness: 2 inches up to 20 inches (multiples of 1-3/8“ laminations are typical) CLT - Typical Panel Connection Details Screws Screws Plywood or LVL

CLT CLT CLT CLT

Plywood or LVL Plywood or LVL Screws

Internal spline Double surface spline

Screws

Plywood or LVL Self-tapping screws

CLT CLT CLT CLT

Single surface spline Half-lapped Floors or Roofs Walls Some Advantages of CLT

§ Lower material weight at comparable strength - up to 6 times lighter than concrete § Panels act as plates with dimensional stability and static strength in all directions § Reduced construction time through use of large panels § Minimal job site waste due to pre-fabrication § Less demand for skilled workers on site § Versatile and easy to integrate with other materials Some Disadvantages of CLT

Cost - depending on competing systems Unfamiliarity of design professionlas with new CLT design codes and standards Lack of performance history in N.A. CLT Standards - A Necessity

§ CLT projects in North America have been largely constructed based on a case-by-case approval by local jurisdictions § To facilitate product acceptance, consensus- based product and design standards were deemed to be essential Benefit of A Product Standard

§ Consensus-based standard for building code adoption § Consistent product quality and reliability § Independent third-party inspection § Improved product availability § Designers can focus on design and innovation ANSI/APA PRG 320

As an ANSI-accredited standards developer, APA initiated the development of ANSI/APA PRG 320, Performance Standard for Cross-Laminated Timber, in 2010 Approved by ANSI in December 2011 Current version is PRG 320-2012

Download at www.apawood.org ANSI/APA PRG 320

§ Balanced Interest § 5 Manufacturers, 9 Suppliers, 7 Users, and 14 General Interests § Secretariat: APA § Developed as a bi-national (U.S. and Canada) standard § Open Process § 35 Voting members: 18 U.S., 16 CAN, and 1 EU § 22 Observers: 12 U.S., 7 CAN, and 3 Australians Key Components for CLT Similar to Glulam Lumber §Different species §Variety of grades Joints §Structural end joints §Structural face bonding §Structural edge joints (optional) Adhesives §Different types §Must meet ANSI 405 in U.S. ANSI/APA PRG 320

Key Considerations

§ Dry-Use applications § Lumber or SCL laminations permitted § Lumber Species – Any softwood species meeting PS20 or CSA O141 and a specific gravity of 0.35 or higher § Outermost layers – minimum 1200f-1.2E MSR or No. 2 VG § Core layers – minimum No. 3 VG ANSI/APA PRG 320

Key Considerations

§ Lamination thickness: 5/8” to 2” due to face bond consideration § Max CLT thickness: 20” § Adhesives §U.S.: ANSI 405 + PS1 Heat Performance §Canada: CSA O112.10 + ASTM D7247 Heat durability + PS1 Heat Performance § Mandatory requirements for end joints and face joints § Non-mandatory for edge joints ANSI/APA PRG 320

Standard CLT Grades

4 “E-Rated” CLT grades E1: 1950f-1.7E SPF MSR (//) + No. 3 SPF (⊥) E2: 1650f-1.5E DF-L MSR (//) + No. 3 DF-L (⊥) E3: 1200f-1.2E ES, NS, or WW (//) MSR + No. 3 ES, NS, or WW (⊥) E4: 1950f-1.7E SP MSR (//) + No. 3 SP (⊥) ANSI/APA PRG 320

Standard CLT Grades

3 “Visually-Graded” CLT grades V1: No. 2 DF-L (//) + No. 3 DF-L (⊥) V2: No. 1/No. 2 SPF (//) + No. 3 SPF (⊥) V3: No. 2 SP (//) + No. 3 SP (⊥)

Appearance classifications are included in the non-mandatory Appendix Alternate Analytical Design Methods for CLT Elements Based on EU Research

Potential Design Methods

1) Mechanically Jointed Beams Theory (Gamma Method) – Bending Stiffness – Bending Strength – Shear Strength

2) Composite Theory (k Method) – Bending Stiffness – Bending Strength

3) Shear Analogy (Kreuzinger) – Bending Stiffness and Shear Stiffness ANSI/APA PRG 320

Properties have been determined in accordance with the “Shear Analogy” model Other models are permissible if verified by an approved agency Allowable design property tables provided for use in the U.S. and Canada Allowable bending capacity tables provided for use in the U.S. and Canada CLT Manufacturing Standard CLT Manufacturing Standard ICC-ES Acceptance Criteria AC 455

Defines In-plane Panel Shear Strength Test for use in Floor and Roof Decks ANSI/APA PRG 320

§ It is impractical to list all possible CLT layups § Custom manufacturer specific CLT layups are permitted when approved by a certification agency in accordance with the qualification and mechanical test requirements specified in PRG 320 § Designers are encouraged to contact CLT manufacturers for available, optimized, and economical custom products for project needs CLT Product Certification

§ The CLT must be qualified based on a mechanics-based model and confirmed by qualification tests of § Glue bond durability § Full-scale bending § Full-scale shear § The CLT must be under a quality assurance program audited by an approved agency North American CLT Manufacturers

PRG 320 – APA Certified Production

Nordic Engineered Wood, Chibougamau, Quebec Structurlam, Penticton, British Columbia D.R. Johnson Wood Innovations, Riddle, Oregon SmartLam, Columbia Falls, Montana Typical CLT Trademark

APA

1 V2 6 7/8” 2

3 MILL XXXX ANSI/APA PRG-320-2012 4

1. Grade qualified in accordance with ANSI/APA PRG 320. 2. Product thickness. 3. Mill number. 4. Referenced product standard. ANSI/APA PRG 320 Version 2 – 2018 IBC

§ Balanced Interest § 14 Manufacturers, 4 Suppliers, 8 Users, and 15 General Interests § Secretariat : APA § Developed as a bi-national (U.S. and Canada) standard § Open Process § 41 Voting members: 26 U.S., 15 CAN § 15 Observers: 8 U.S., 6 CAN, and 1 Australia CLT Design Standards

CLT design covered in: § New Chapter 10 added to the 2015 National Design Specification for Wood Construction (NDS) § Numerous changes to connection chapters for CLT added to 2015 NDS § CLT added to Chapter 16 on Fire Performance in NDS § Added to CSA O86 Engineering Design in Wood in Canada 2015 NDS 2015 NDS CLT Connection Provisions 2015 Building Code ANSI/APA PRG 320

§ ANSI/APA PRG 320-2012 was approved by the IBC Structural Committee for adoption into the 2015 IBC § CLT manufactured to PRG 320 is recognized as a code-compliant construction material in the U.S. § Canadian code adoption in CSA O86 completed 2015 IBC Provisions for CLT

Code modifications to Ch. 23 Wood 2303.1.4 Structural glued cross laminated timber. Cross-laminated timbers shall be manufactured and identified as required in ANSI/APA PRG 320-2011.

Section 202 - Definitions CROSS-LAMINATED TIMBER. A prefabricated engineered wood product consisting of at least three layers of solid-sawn lumber or structural composite lumber where the adjacent layers are cross-oriented and bonded with structural adhesive to form a solid wood element.

Code modifications to Ch. 35 Reference Standards ANSI/APA PRG 320-2011 Standard for Performance-Rated Cross- Laminated Timber 2015 IBC Provisions for CLT

Type IV (HT)

CLT in bearing walls – 6” CLT in heavy timber floors – 4” CLT in heavy timber roof decks – 3” Non Fire-Retardant Treated CLT allowed in Exterior Walls of Type IV construction in some conditions Other CLT can also be used in Types III and V construction

Allows buildings up to 5 or 6 stories (85 feet) depending on the type of construction and occupancy Multi-Story CLT Buildings in the U.S.

4 Story CLT Hotel at 4 Story Albina Yard Office Building US Army Redstone Arsenal Portland, OR Taller Wood Building Options

What if you want to go taller than 85 feet allowed by the current code?

Alternate means is the current pathway for construction of taller mass timber buildings

Section 104.11 Alternative materials, design and methods of construction Future Building Code Considerations

The International Code Council Board of Directors has established an adhoc committee for tall wood buildings based on action taken at its December 2015 meeting. Tall wood is a term used by the industry to identify wood construction which utilizes Cross Laminated Timber (CLT) in buildings of heights greater than 6 stories. CLT buildings with heights ranging up to 12 stories are in the planning stages in Portland and New York City as examples. Planned Tall CLT Buildings - U.S.

Houston House – NYC Framework Project Passive House for Urban Portland, OR Infill Conditions - 8 stories 12 stories - 130 ft. Future Building Code Considerations

The International Code Council Tall Wood Building Ad Hoc Committee is considering adding three Mass Timber classes but no consensus has been reached yet.

Type IV A – fully encapsulated timber

Type IV B – partially encapsulated timber

Type IV C – fully exposed timber

Plus, there are more than 45 code changes for tall wood buildings being considered . Deadline for submittal of code changes is January 2018. CLT Handbooks

§ Current CLT design is carried out by a relatively small group of engineers and architects § CLT Handbooks have been developed for use in both the U.S. and Canada to help acquaint designers with CLT. U.S. CLT Handbook

Funded by $1.3 million from the USDA FPL, Bi-National Softwood Lumber Council, CLT manufacturers, Forestry Innovation Investment (FII) of BC government, and industry associations, the U.S. CLT Handbook has been developed and published by a consortium of 5 organizations: § FPInnovations § APA § American Wood Council § USDA Forest Products Laboratory § WoodWorks

The U.S. CLT Handbook is available for free download at www.rethinkwood.com (500+ pages) U.S. CLT Handbook Chapter 5 – Connections Chapter 5 – Connections Chapter 6 – DOL and Creep Performance Creep Performance of CLT Bending members (NDS® 2015, Eq. 3.5-1)

ΔT = Kcr ΔLT + ΔST

ΔT: total deflection, in

Kcr: proposed creep factor = 2.0 for CLT (1.5 for glulam) (service MC<16%)

ΔLT: deflection due to long-term component of design load, in

ΔST: deflection due to short-term component of design load, in CLT Trends

1. Initial focus has been on horizontal floor and roof applications with exposed panels 2. Growing interest in both exposed and non- exposed (GWB encapsulated) applications 3. Moving from public to private sector owners 4. Significant interest being expressed by design professionals 5. Tall Wood Buildings beyond current North American code limits are being constructed 6. Growing interest in wall applications: but testing for seismic response factors needed Research at FPInnovations in Canada on CLT as LLRS

Cyclic tests on connections with different brackets and fasteners and tests on various configurations of CLT walls §Effects of vertical load §Influence of different brackets and their position §Effect of fasteners in the brackets §Use of hold-downs §CLT walls with half lap joints §Two-story CLT assemblies with floor panels §Tall CLT walls (4.9 m, 16’) §Influence of walls on CLT floor panels CLT Walls as LLRS Configurations Tested

I II III IV V

VI VII VIII

XI a) Bracket A b) Bracket B X

117 a) Bracket A b) Bracket B

c) Bracket C d) Bracket D

General CLT Wall Performance Results CLT wall panels behaved almost as rigid bodies during the testing Although slight shear deformations in the panels were measured, most of the panel deflections occurred as a result of the deformation in the joints connecting the walls to the supports In case of multi-panel walls, deformations in the step joints also had significant contribution to the overall wall deflection Current Canadian recommendations for Seismic Force Factors: Rd = 2.0 (ductility) Ro = 1.5 (over-strength) Shear Wall Testing of CLT at Colorado State University

Test Type Objective Connector tests • Behavior under cyclic loading • Interpanel connector behavior

• Isolated Wall Tests Boundary condition • Gravity loading • Connector thicknesses • Connector type • CLT panel thickness • Connector thickness • CLT panel aspect ratio • Inter-panel connector (vertical joint) • CLT grade Box type • Effect of diaphragm on wall behavior configuration • Diaphragm behavior • Effect of out-of-plane loading on the connector • Effect of bi-directional loading • Hold-downs in the corners • Stability of the walls Box type • Effect of out-of-plane loading on the connector configuration with • Effect of bi-directional loading • Hold-downs in the corners multiple panel • Stability of the walls walls • Vertical joints between perpendicular walls will also be investigated 3-sided wall with a • Effect of diaphragm rotation diaphragm • Combined loading on the connectors Shear Wall Testing of CLT at Colorado State University

Research conducted to comply with FEMA P695 provisions for establishing seismic design coefficients for new technologies.

Goal after completing the research and developing seismic design coefficients is to submit it to the BSSC > ASCE 7 > IBC Shake Table Tests on 7 story CLT Framed Building Conducted at E-Defense in Japan

Panel thickness 140 mm (5.5”) floors 1 and 2 125 mm (4.9”) floors 3 and 4 85 mm (3.3”) top 3 floors Wall panel length 2.3 m (7.5’) After successfully passing several earthquake simulations the the structure was dismantled and shipped back to Italy where it is now a multi-family housing facility Mass Timber (CLT) Research Workshop

§Held on November 3-4, 2015 at the USDA FPL in Madison, WI. §Sponsored by the FPL, WoodWorks and the Softwood Lumber Board §Over 120 researchers, practitioners and government employees attended §26 invited speakers covering all aspects of Mass Timber research §Two days of brainstorming on future Mass Timber research needs Development of a CLT Mass Timber Tornado Safe Room

USDA Forest Products Laboratory DR Johnson Wood Innovations Timber Engineering LLC CLT Tornado Safe Room Test

3 ply CLT panel loaded in the weak axis direction Loaded in accordance with ICC 500 Load achieved an equivalent pressure of a 250 mph wind without failure (approximately 450 psf) Panel also passed the 100 mph missile impact test Mass Timber (CLT) Research Workshop Proceedings

Proceedings Mass Timber Research Workshop 2015 . USDA Forest Products Laboratory Madison, Wisconsin November 3–4, 2015 Edited by Robert J. Ross, Supervisory Research General Engineer Forest Products Laboratory Madison, Wisconsin Tom Williamson, Managing Partner Timber Engineering LLC Vancouver, Washington

General Technical Report FPL–GTR–241 www.fpl.fs.fed.us Characteristics of Mass Timber Glulam and CLT in Fire

§Wood is an excellent heat insulator §Develops a char layer during fire exposure §Self-extinguishing after fire source removed §Retains significant residual strength after being exposed to fire NDS Methodology for Determining Fire Resistive Ratings

Chapter 16 § Mechanics Based Model § Supported by empirical data § 1, 1-1/2 and 2 hour ratings possible § CLT added to 2015 NDS NDS Methodology for Determining Fire Resistive Ratings

t βeff 1.8 in./hr 1.2βn 1 hr βeff = (45.7 mm/hr) t 0.187 1.58 in./hr 2 hr (40.1 mm/hr) Where:

βeff = Effective char rate (in./hr), adjusted for exposure time, t

βn = Nominal char rate (1.5 in./hr) t = Exposure time (hr) Typical Glulam Beam Layup

24F-V4 Doug Fir (12 Lamination Example)

2 - L2 Dense Grade Outer Comp. Lams 1 - L2 Grade Inner Comp. Lam

6 - L3 Grade Core Lams

1 - L2 Grade Inner Ten. Lam 1- L1 Grade Outer Tension Lams 1- 302-24 Outer Tension Lams For 1-hour fire rated beam: substitute additional tension lam for core lam. Minimum size for 1 hr rating is 6-3/4”x13-1/2” Canadian Testing for Fire Resistance of CLT

Full-scale testing in accordance with ULC S101 / ASTM E119 (joint FPI/NRC Test Program) § Evaluate charring rate § Fire performance of adhesive § Develop calculation procedure for US and Canadian standards § Additional full-scale tests were also conducted with wood industry partners and CLT manufacturers Full-scale Fire Tests on Canadian CLT

Specimens

§ 3, 5 and 7 ply CLT § Fully loaded specimens (based on strength or serviceability) § Values shown exclude the specimen self-weight § Polyurethane (PUR) adhesive § ULC S101 (ASTM E119) § Gypsum Board 1 layer of 15.9 mm Type X, or 2 layers of 12.7 mm Type X Full-scale Canadian CLT Fire Test Results

Walls § 3-plys (114 mm) protected + 2 x ½" Type X : 106 min § 5-plys (105 mm) unprotected : 57 min § 7-plys (175 mm) unprotected : 113 min Floors § 3-plys (105 mm) + ⅝" Type X : 86 min § 5-plys (175 mm) unprotected : 96 min § 5-plys (175 mm) + ⅝" Type X : 124 min (≈ 2 hrs) § 7-plys (245 mm) unprotected : 178 min (≈ 3 hrs) 2015 NDS Fire Provisions for CLT

Table 16.2.1B added for CLT char rates

Equations added for calculating char depth of CLT members

Design values determined by multiplying reference stresses by tabulated adjustment factors Manufacturer’s Proprietary CLT Fire Test Results

QAI Laboratories, Inc. San Antonio, TX ASTM Designation E84-15b, "Standard Method of Test for Surface Burning Characteristics of Building Materials“. CLT Panel: 24” wide by 4” thick by 24’ long Test Results: Flame Spread 20 Smoke Developed 50 Meets the “Class A” Flame Spread requirements which are flame spread less than 25 and smoke developed less than 450 ASTM E 119 Test 5 ply DF V1 CLT panel with a 2” gypcrete topping slab Met 2 hour fire rating under full design load Manufacturer’s Proprietary CLT Fire Test Results Typical CLT Construction Typical CLT Construction Early “Tall” CLT Buildings

9-Story Murray Grove Apartment 10-Story Forté Building Building – London, UK Melbourne, Australia Murray Grove – Modern Mixed Use Timber Structure

First “tall wood” building in 2009 29 flats (mixed affordable and private) Ground floor offices Load bearing CLT walls, floors and cores 4x less weight than precast concrete 1/2 the construction time of precast concrete (saved 22 weeks vs. conc.) Stores 300 metric tons of CO2 10-Story Forté Apartment Building Melbourne, Australia

• 23 apartments • Used 485 metric tons of timber, 759 CLT panels, 34,550 screws, and 5,500 angle brackets • CLT installation completed in 2 months • Entire building completed in 10 months Multi-Story CLT Buildings - Canada

Multi Family Residence Quebec, CA UBC Earth System Science Building British Columbia, CA Arbora Residential Project Montreal, Canada

Planned to be the World’s Largest CLT residential project

Total surface area of 597,560 sq. ft.

3 eight-story buildings with a total of 434 condo, townhouse and rental units Retail space on first two floors Tall CLT Buildings in Canada

18-Story Building 13 Story Apartment Building Brock Commons Quebec City, CA UBC Student Residence Brock Common - Vancouver, CA

1 concrete story + 2 concrete cores supporting 17 stories of mass timber ; timber erected in 66 days Brock Common - Vancouver, CA 4 Story CLT Hotel at US Army Redstone Arsenal Albina Yard Office Building - Portland Tall CLT Buildings - U.S.

Framework Project Portland, OR 12 stories - 130 ft.

2 stories of retail 5 stories of offices 5 stories of residential

All glulam and CLT framing with CLT exposed at all levels Framework Project - Portland, OR The Future for "Tall" Mass Timber Buildings

Perkins + Will’s River Beech 40 Story Mixed Use Tower Stockholm, Sweden Barbican Wood Chicago Tower 80 Stories SOM 42 Story 300 meters Chicago London, England CLT/Concrete Hybrid CLT and Glulam are Environmentally Friendly - Sustainable and Green

Produced from small dimension lumber harvested from managed and sustainable forests Timber resource utilization optimized using a wide range of lumber grades and a wide variety of species

This concludes The American Institute of Architects Continuing Education Systems Course

Tom Williamson, P.E. Timber Engineering LLC [email protected]