Transcription
Introduction to Mass Timber ConstructionPaul Coats, PE, CBOSoutheast Regional ManagerAmerican Wood Council
American Wood CouncilAWC is committed to ensuring a resilient,safe, and sustainable built environment.2
Copyright MaterialsThis presentation is protected by US and InternationalCopyright laws. Reproduction, distribution, display and use ofthe presentation without written permission is prohibited. American Wood Council 20173
DescriptionCross-laminated timber (CLT) has been in use worldwide for over 15 years, butmost notably in Europe. Building with CLT has increased in popularity for manyreasons including: just-in-time fabrication and job site delivery, speed andefficiency in construction, reduced job site noise and on-site labor force,substitution of high embodied materials with a renewable resource thatsequesters carbon, and creating a living or work space that has the aestheticsof exposed wood.The recent introduction of CLT in the 2015 National Design Specification forWood Construction (NDS ) and the 2015 International Building Code hasopened up an exciting new chapter in wood construction. The use of CLT aloneor in combination with other mass timber elements, such as glued-laminatedtimber (GLT), nail-laminated timber (NLT), or structural composite lumber(SCL), is becoming more common in buildings complying with the current code.There is also an effort underway by the International Code Council (ICC) torecognize the use of mass timber elements in taller, combustible constructionthrough the work of the ICC Tall Wood Ad Hoc Committee. This presentationwill provide an introduction to CLT including relevant design standards and codereferences. Examples of various mass timber buildings around the world will beprovided and potential future code provisions relating to mass timber will alsobe discussed.4
Learning ObjectivesAt the end of this program, participants will bebetter able to1. Define cross-laminated timber2. Identify code and standard updates relevant to CLTand other mass timber elements3. Recognize notable mass timber structures around theworld4. Understand how wood performs in fire conditions5. Comprehend current tall wood building codedevelopments and resources5
Cross-laminated Timber (CLT)CROSS LAMINATEDTIMBER PANELSPhoto provided by FPInnovations6
Mass Timber Concept - History of CLT 1985 1st CLT patent - France 1993 1st CLT projects - Switzerland andGermany 1995-1996 Improved press technology 1998 1st multi-story res building - Austria Early 2000’s CLT use (Europe) increased significantly Green building movement driven Better efficiencies, product approvals,improved marketing and distribution channels Over 500 CLT buildings in England Recent - US and Canadian use of CLT7
CLT vs. GLTCross Laminated TimberThick Orthotropic PlateGraphics provided by WoodWorksGlued Laminated TimberBeam-like memberGraphics provided by APA8
Climate ChangeStradthaus – 24 Murray GroveLondon infill project29 flats4x less weight than concrete 1/2 construction time of precast concrete(saved 22 weeks 30%)Saves 300 metric tons of CO221 years of building energy usageTHE CASE FOR Tall Wood BUILDINGS How Mass Timber Offers a Safe, Economical, and Environmentally Friendly Alternative for TallBuilding Structures FEBRUARY 22, 2012 PREPARED BY: mgb ARCHITECTURE DESIGN; Equilibrium Consulting; LMDG Ltd; BTY Group9
Mass Timber – USElementary School, Franklin, West VirginiaSource: LignaTerra10
Mass Timber – USPrivate Army HotelRedstone Arsenal Huntsville, ALFour stories 58,000 sq ftArchitect: Lend LeaseSource: LignaTerra11
Building Codes12
Governing Codes for Wood Design2015 IBC references in 2015 NDS13
Chapter 10 – Cross-Laminated Timber1, 2, 3, 4transverse layersSingle or multiplesurface layersLaminations: 5/8”-2” sawn lumber or SCLPanel thickness: 20” maxIn-Service MC: 16%Graphics provided by FPInnovations14
Chapter 10 – Cross-Laminated TimberNew15
GLT and CLT Adhesives16
Product MarkingMarks contain thefollowing:a)CLT grade qualifiedb)CLT thickness or identificationc)Mill name or identification numberd)Approved agency name or logoe)“ANSI/APA PRG 320”f)Manufacturer’s designationg)“Top” stamped on top face(For unbalanced layups)17
CLT Handbook Additionalinformation onissues not yetcovered in NDS orIBC Energy Sound Vibration Enclosures Handling18
Nail Laminated Timber (NLT)Photo courtesy of Structurecraft19
Nail-Laminated Timber20
Nail-Laminated Timber 2304.8.3 Mechanicallylaminated decking. 2304.8.3.1 General. 2304.8.3.2 Nailing. 2304.8.3.3 Controlledrandom pattern.Nail lengthmin 2.5 x tlaminationNail spacing 30” o.c.* 48” span 18” o.c.* 48” span*nail placement alternates betweentop and bottomt21
Warner Drive – Culver City, CA Nail-Laminated Timber – 2x12vertical mechanically-connectedw/nails NDS principles of mechanicsArchitect: Profeta Royalty ArchitectureStructural Engineer: Structural FocusCompleted: 201122
Nail-Laminated Timber Clay Creative Portland, Oregon Mixed-Use 72,000 SF 6 Story (5 over 1 plus1 level partial belowgrade parking)Developer: Killian PacificArchitect: MackenzieStructural Engineer: Kramer Gehlen & AssociatesCompletion: 201623
Nail-Laminated Timber24
Nail-Laminated Timber The Hudson Vancouver, WA Mixed-Use 45,000 SF 3 storyDeveloper: Killian PacificArchitect: MackenzieCompletion: 201625
Nail-Laminated Timber26
Nail-Laminated TimberResource: StructureCraft27
Nail-Laminated TimberResource: StructureCraftGeneral Contractor: CompanionLocation: Surrey, British Columbia, CanadaDesign Assist, Fabrication and Installation: StructureCraftCompletion: 201328
Glued-laminated Timber (GLT)29
Glued-laminated Timber Clay Creative Portland, Oregon Office Building 60,000 SF 6 Story (5 over 1 plus1 level partial belowgrade parking)30
Glued-laminated Timber One North Portland, Oregon Mixed Use East Bldg. 43,000 SF West Bldg. 43,000 SFDevelopment Team: Karuna Properties II, LLC; NelsGabbert, LLC; Kaiser Group Inc.; Owen Gabbert, LLCContractor: R&H ConstructionArchitect: Holst ArchitectureStructural Engineer: Froelich Consulting EngineersCompletion: 201631
Glued-laminated Timber32
Structural Composite Lumber (SCL) PSL Photo provided by Weyerhaeuserparallel strandlumber LSL laminated strandlumberPhoto provided by Truss Joist LVL laminated veneerlumber OSL Photo provided by StructurecraftPhoto provided by Wood Solutionsoriented strandlumber33
Other Innovations Dowel Laminated Timber Wood-Concrete Composites34
Historical Tall WoodKelly, Douglas and Co. Warehouse;Vancouver , BC (c. 1905)Leckie Building, Vancouver, BC(c. 1908)The Purse Building, Dallas, TX, (c. 1905)35
Butler Brothers Building – Minneapolis - 1906From Designing for Durability – reThinkWood.comBuilding interior: Preservation Alliance of Minnesota; Building exterior: Butler Square36
US Projects Framework Portland, Oregon 12 Story Currently tallest WoodBuilding in US Street-level retail, office,workforce housing andcommunity space U.S. Tall Wood Building PrizeCompetition winner *Photo provided by Next mework-dz1/* Sponsored by the U.S. Department of Agriculture, the Softwood LumberBoard and the Binational Softwood Lumber Council37
Mass Timber – USMixed retail/officespaceMinneapolis, Minnesota T3 Project 7 Stories https://vimeo.com/16258083838
US ProjectsCarbon 12 Portland, Oregon 8 Stories Residential 12/39
Canadian ProjectsThe Arbora Québec, Canada 8 Stories 434 Residential condo, townhouse and rental units40
Canadian Projects41
CanadianProjectsThe Arbora42
Canadian Projects43
Canadian ProjectsBrock Commons Vancouver, BritishColumbia, Canada 18 Stories Mixed use student housing44
Tall Wood -timber/tall-wood-gallery4545
Heavy Timber Fire Resistance RatingPhoto by Structure Magazine46
NDS Chapter 16 – Calculated Resistance Fire resistance ofexposed woodmembers may becalculated using theprovisions of NDSChapter 16Predictable47
Fire Design of Exposed Wood MembersNewCrosslaminatedTimberEffectiveChar Depth48
Fire TestAmerican Wood CouncilASTM E119 Fire EnduranceTest 5-Ply CLT (approx. 7” thick) 5/8” Type X GWB each side Sought 2 hour rating RESULTS: 3 hours 6 minutesSelf-tappingscrewsCLTCLTHalf-lapped – middleof panel49
Residential Fire Load DemonstrationCLT : September 15, 201550
ICC Tall Wood Ad Hoc51
AWC Proposals Existing Type IV construction to remain New categories for CLT/Mass Timber Examples based on Use Groups R1 and R2 Type IV C - 9 Stories meeting existing coderequirements for HT except with 2-hour fireperformance 12 Stories meeting existing code requirements(except for non-combustibility) of Type IBconstruction 20 Stories meeting existing code requirements(except for non-combustibility) of Type IAconstruction Additional enhancements above current coderequirements can be considered for each category52
Sprinklered Group R (NFPA 13 sprinkler system) Conventionallight frame,unrated (TypeVB) or 1-hourrated structure(Type VA)VAType III (noncomor FRTW 2-hourexterior bearingwalls; light frameinterior structure)Type IV (noncomor FRTW exteriorwalls; heavytimber interiorstructure “Mass” Timber,fire resistancerated, minimumheavy timberdimensions, andpartiallyprotected withgypsum? Mass timber,fire resistancerated and fullyprotected withgypsum?VB53
Possible Fire Safety Distinctions for Mass TimberType IV:Type IV-C:Type IV-B:Type IV-A:-minimum heavytimber dimensions;-minimum heavytimber dimensions-minimum heavytimber dimensions-minimum heavytimber dimensions-no concealedspaces-MINIMUM fireresistance ratings-INCREASED fireresistance ratings-MAXIMUM fireresistance ratings-protectedconcealed spaces-protectedconcealed spaces-protectedconcealed spaces-PROTECTIONrequired (gypsumcovering, multiplelayers, mostsurfaces)-COMPLETEPROTECTIONrequired (gypsumcovering, multiplelayers, for allsurfaces)12 STORIES ?20 STORIES ?54
Ongoing testing National Fire Protection ResearchFoundation (at NIST test facilities) AWC testing (ATF facility) 55
Questions? This concludes The American Institute of ArchitectsContinuing Education Systems Coursewww.awc.orginfo@awc.org56
The recent introduction of CLT in the 2015National Design Specification for . The use of CLT alone or in combination with other mass timber elements, such as glued-laminated timber (GLT), nail-laminated timber (NLT), or structural composite lumber (SCL), is becoming
