Please add relevant logo here Mass Timber Construction: Products, Performance and Design This course is registered with AIA “The Wood Products Council” is a CES for continuing professional Registered Provider with The education. As such, it does not American Institute of Architects include content that may be Continuing Education Systems deemed or construed to be an (AIA/CES), Provider #G516. approval or endorsement by the AIA of any material of construction or any method or Credit(s) earned on completion of manner of this course will be reported to AIA handling, using, distributing, or CES for AIA members. Certificates dealing in any material or of Completion for both AIA product. members and non-AIA members ______________________________ are available upon request. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation. Course Description Due to their high strength, dimensional stability and positive environmental performance, mass timber building products are quickly becoming materials of choice for sustainably-minded designers. This presentation will provide a detailed look at the variety of mass timber products available, including glue-laminated timber (glulam), cross laminated timber (CLT), nail laminated timber (NLT), heavy timber decking, and other engineered and composite systems. Applications for the use of these products under modern building codes will be discussed, and examples of their use in U.S. projects reviewed. Mass timber’s ability to act as both structure and exposed finish will also be highlighted, as will its performance as part of an assembly, considering design objectives related to structural performance, fire resistance, acoustics, and energy efficiency. Other topics will include detailing and construction best practices, lessons learned from completed projects and trends for the increased use of mass timber products in the future. Learning Objectives 1. Identify mass timber products available in North America and consider how they can be used under current building codes and standards. 2. Review completed mass timber projects that demonstrate a range of applications and system configurations. 3. Discuss benefits of using mass timber products, including structural versatility, prefabrication, lighter carbon footprint, and reduced labor costs. 4. Highlight possibilities for the expanded use and application of mass timber in larger and taller buildings. mass timber Today’s agenda Mass timber construction Mass timber • Why use it – appeal • What is it – products • How does it work – design topics • Where is it used – case studies • What’s next? Mass timber appeal Mass timber appeal What is the ultimate appeal and driver for any building and material type? Mass timber appeal Primary drivers Construction speed & efficiency Construction site constraints – urban infill Innovation/aesthetic Secondary drivers Carbon reductions Structural performance – light weight Mass timber appeal Reduced construction time Murray Grove, London UK 8 stories of CLT over 1 story concrete podium Less time on site = 8 stories built in 27 days (~1/2 the time of precast concrete) less $$ Franklin Elementary School, Franklin, WV 45,200 ft2 2 story elementary school 8 weeks to construct Mass timber appeal Alternate to concrete & masonry Photo Credit: charles judd Mass timber appeal Material mass 75% lighter weight than concrete Mass timber appeal Material mass 75% lighter weight than concrete Mass timber appeal Material mass Completed in 2012 10 stories ~ 105 ft. tall, > 18.6 K sqft. 3 million in R&D Poor soils required a much lighter building Forte’, Victoria Harbor, Melbourne, Australia Architect: Lend Lease Mass timber appeal Reduced embodied carbon Stadhaus, London, UK Volume of wood used 950 m3 Carbon sequestered and stored (CO2e) 760 metric tons Avoided greenhouse gases (CO2e) 320 metric tons Total potential carbon benefit (CO2e) 1,080 metric tons Carbon savings from the choice of wood in this one building are equivalent to: 1,615 passenger vehicles off the road for a year Enough energy to operate a Architect: Waugh Thistleton Architects home for 803 years Photo credit: Waugh Thistleton Architects Mass timber appeal Minimal waste Mass timber elements fabricated to Mass timber appeal tight tolerances (1/16” is common) Prefabricated and precise Computer Numerically Controlled (CNC) connections Photo credit: naturally wood Mass timber appeal Energy efficient CLT has an R-value of approximately 1.25 per inch of thickness. Source: US CLT Handbook Mass timber appeal Disaster resilient Mass timber appeal Structural flexibility Photo Credit: APA Mass timber is a Mass timber category of framing What is it? styles often using small wood members formed into large panelized solid wood construction including CLT, NLT or glulam panels for floor, roof and wall framing Building frame systems Mass timber systems horizontal framing Vertical framing • Glulam beams • Glulam columns • nlt panels • Clt walls • Clt panels • Glt panels • T&g Decking • Composite timber/concrete • scl panels Mass timber products Vertical framing Glulam Beams & Columns Cross Laminated Timber (CLT) walls Mass timber products horizontal framing Nail Laminated Timber (NLT) Cross Laminated Timber (CLT) Glue Laminated Timber (GLT) Tongue & groove Timber concrete composite decking (T&G) Structural composite Lumber Image source: structurecraft Mass timber products glulam Photo Credit: alex schreyer Mass timber products glulam Glulam = a structural composite of lumber and adhesives • Recognized in IBC 2303.1.3 using ANSI/AITC A 190.1 and ASTM D 3737 • Can be used for floor, roof purlins, beams, arches, columns Mass timber products glulam Single Lamination Glued Laminated Timber Mass timber products glulam specs: glulam Typical Widths: 3-1/8”, 3-1/2”, 5-1/8”, 5-1/2”, 6-3/4”, 8-3/4”, 10-3/4”, 12-1/4” Typical Depths: Increments per # of lams from 6” to 60”+ western species lams are typically 1-1/2” thick depth Southern pine lams are typically 1-3/8” thick Typical Species: Douglas-Fir, Southern Pine, Spruce width Also available in cedar & others Image: APA Glulam Product Guide Mass timber products Glulam design values glulam Source: nds supplement table 5a Mass timber products Glulam beam capacities glulam Source: apa AITC Beam Capacity Tables http://www.aitc-glulam.org/capacity.asp S = controlled by shear, D = controlled by deflection, B = controlled by bending Mass timber products Glulam column capacities glulam AITC Column Capacity Tables http://www.aitc-glulam.org/column.asp Mass timber products glulam Glulam specs: Pt readily available FRT may be available, varies by manufacturer & treater Can be cambered, curved & tapered Different Appearance Photo credit: anthony forest products Grades available Photo: Ema Peter Photography Mass timber products glulam Glulam Framing Grade appearance Industrial Grade grades Architectural Grade Premium Grade Images: American Laminators Mass timber products glulam Specifying glulam: Several methods 24f-1.8e Allowable bending stress = 2400 psi moe = 1.8x106 psi Df 24f-v4 Douglas-fir Allowable bending stress = 2400 psi visually graded lumber layup combination 4 Mass timber products glulam Glulam layup: Vary strength of laminations High Strength Outer • Higher strength lams at top and bottom - Compression Lams tension and compression stresses are high Medium Grade Inner • Lower strength lams in center plies Compression Lam Lower Grade Inner Lams Medium Grade Inner Compression Lam High Strength Outer Tension Lams Image: Apa Mass timber products glulam Unbalanced layup: simple span Balanced layup: multi-span, cantilever, multi-directional loads Typical unbalanced layup: combination 4 Typical balanced layup: combination 8 Image: AITC Mass timber products glulam Layup combinations Source: aitc 117 Mass timber products glulam Glulam camber • Glulam can be manufactured with camber to offset dead load deflection • Very important for long span members • Glulam industry recommends camber = 1.5 times calculated dead load deflection Image: APA Glulam Product Guide Flexibility of spans and shapes Richmond Olympic Oval, Richmond, BC, Canada Design Team: Cannon Design Architecture, Fast + Epp, Glotman Simpson Photo Credit: Stephanie Tracey, Craig Carmichael, Jon Pesochin, KK Law Creative, Ziggy Welsch 104’ Span Glulam Arches Glulam purlins @ 4’ o.c Lemay america auto musuem Photo Credit: western wood structures The Cathedral of Christ The Light, Oakland, CA Photo: Timothy Hursley, Cesar Rubio, and John Blaustein Long span glulams Photo: American wood council Mass timber products glulam Built up sections: available from some manufacturers for wide beams, large columns. Widths of 24”+ available Photo: unalam Radiator building Portland, or Photo Credit: Josh Partee Radiator building Portland, or Building info: Office building 5 stories 36,000 sf Completed 2015 Photo Credit: Josh Partee Gravity Framing: Glulam Frame (Columns & Beams) Radiator building Lateral Framing: Sheathed Portland, or Shear Walls Photo Credit: Josh Partee Radiator building Portland, or Photo Credit: woodworks Exposed steel connections Glulam girder & purlin frame Photo Credit: Josh Partee One north Portland, or Structural Floor/Roof & Diaphragm: Exposed T&G Decking, Wood Structural Panels Photo Credit: Josh Partee One north Portland, or Long term sustainability Why a Timber Framed Office Building? “Wood consumes and sequesters carbon. There’s a lot of momentum for this. Timber framing is so much more sustainable.” Ben Kaiser