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Meeting 6-Storey Challenges with LSL
Ontario Wood Solutions Fair November 12, 2013
Copyright Materials • This presenta2on is protected by US and Interna2onal Copyright laws. Reproduc2on, distribu2on, display and use of the presenta2on without wri?en permission of the speaker is prohibited.
• © Weyerhaeuser 2013
Program Educa2on Credit Informa2on • The Canadian Wood Council is a Registered Provider with the American
Ins2tute of Architects. This course meets Con2nuing Educa2on System requirements for one Learning Unit. Credit earned on comple2on of this program will be reported to CES Records for AIA members who provided their member number during the online registra2on. This course also qualifies as Structured Learning with OAA. Cer2ficates of Comple2on for OAA members, and anyone else who indicated they wanted a cer2ficate, will be emailed aPer the event to those who requested them during the registra2on process. We will also report par2cipa2on to the Engineering Ins2tute of Canada on behalf of any engineers who requested their par2cipa2on be recorded.
This program is registered with the AIA/CES for con2nuing professional educa2on. 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 construc2on or any method or manner of handling, using, distribu2ng, or dealing in any material or product. The same is true for the OAA and EIC. Ques2ons related to specific materials, methods, and services will be addressed at the conclusion of this presenta2on.
Agenda
• LSL Product overview • Six Storey Challenges:
– Dimensional Stability (“Shrinkage”) – Product Capacities and Quality – Construction Efficiency
• Questions?
= 0.8E = 1.3E, 1.5E, 1.55E
Batch Manufacturing Opera2on 3-‐1/2” x 8’ x 60’/64’ Billet
LSL - Manufacturing
Laminated Strand Lumber (LSL)
• Manufactured to well established standards (ASTM, CSA)
• Tightly controlled, uniform properties • Properties evaluated by third parties
LSL - Manufacturing
• Up to 8’wide, 64’ long, 4” thick • Fully graded and sanded up to 5’ width
LSL: Common Uses: • Beams and headers • Studs and columns • Rimboard
• Stair stringers • Treated sill plates • Industrial applications
LSL – Typical Applications
LSL – Typical Dimensions
• Beams and Headers: – Thickness: 1-3/4”, 3-1/2” – Depths: 9-1/2”, 11-7/8, 14”, 16”
• Rimboard – Thickness: 1-1/8”, 1-1/4”, 1-1/2” – Depths up to 24”
• Studs/Columns – Thickness: 1-1/2”, 1-3/4” – Depth: 3-1/2”, 5-1/2”, 7-1/4”
Dimensional Stability – “Shrinkage”
• Cumulative Effects • Cross-grain shrinkage of particular concern
– Radial and tangential directions
Dimensional Stability – “Shrinkage”
• Platform construction: – Wall plates – Rimboard – Joists
Dimensional Stability – LSL Rim Board
• EMC for lumber ~12%; for ELP ~10% • KD dimension lumber dried to ~16%-19%
moisture content – shrinkage occurs as wood dries
• LSL made ~4-6% – manufactured to match nominal depth at
anticipated MC ~10% – Discontinuous grain reduces dimensional change
and thus less shrinkage at rim locations
Dimensional Stability – LSL Rim Board
• Relative study based on worst-case conditions: – Measured depth: in yard, saturated (>30% MC),
redried to original MC – Fully saturated swell = 1.0% – Retained depth swell = 0.3%
• 5 stories of 9.25” depth rim, – Lumber: 3.2% shrinkage = 1.5” total – LSL: 0.7% shrinkage = 0.32” total
• Properly managed construction should not result in saturation of materials
Dimensional Stability – LSL Wall plates
• Another contributor to shrinkage is wall plates. – Potentially three per floor x 6 floors =
18 plates – ~1/16” shrinkage x 18 plates ! >1”
• LSL used in this application must be kept dry – Works well with panelized
construction • Research focus to improve
performance
Photo Courtesy APEGBC
Dimensional Stability - multistory structures
• Potential Benefits of using both products in combination (Rim and Plates) – Less concern on architectural finishes – Reduction of shear wall drift – Less vertical displacement for tie-down devices – Higher tensile and bending properties for chord
design – Long lengths up to 48’ equals less splice
connections – Every piece true to size – Warranted Product
Product Structural Capacities
• Increased demand on structural elements, particularly at lower floor levels
• Stud walls, plates, rim – greater loads • LSL capacities have increased as the
product continues to develop
LSL Wall Plates • Recent standard changes allow Fcp determination for SCL
based on proportional limit
0
200
400
600
800
1000
1200
SPF Dfir 2100 MSR 1.3E LSL 1.5E LSL
Factored Bearing Resistance
Kb=1.17, Kzcp=1.15
Phi = 0.8 Only
LSL Rim Properties • Enhancements to vertical load capacities and bending
values are forthcoming – currently under review
• Advantages: – Closer allowable nail spacing in narrow edges (useful for both
shear walls using LSL studs, and rim connections to resist shear) – Less likelihood of splitting when toe or edge nailed – Fully qualified rim material – Does not cup like LVL material
Construction Efficiency Wall Panelization
– Replacement for lumber or other EWP – quality reduces downgrade – thicker sections can reduce
nailing – economical relative to other
EWP – enhanced properties result in
less material usage, less thermal breaks
Construction Efficiency
Floor Panelization • Economical
substitute for LVL in most cases
• High shear values allow for larger holes
Software for Design and Fabrication
Plan Typique
Efficient Load Distribution • Joist Direction: Bearing at interior walls
rather than all loading to perimeter
LSL Wall Studs
• Tall Wall Design • Zone Framing
LSL Shear Walls
LSL Panels
• Design properties available – high shear and bending strength • 1-3/4”, 2-1/2” and 3-1/2” thicknesses (44 mm - 89
mm) • 4’ (1200 mm) wide, up to 64’ (19 500 mm) long.
– widths up to 8’ (2435 mm) available in certain applications)
• Flexibility in thicknesses that no other wood product can economically achieve
• Meets heavy timber fire-resistance requirements
Opportunities – Roof/Wall Panels
Elevator Core – Mid rise 5.25” x 10’ x 17’ solid wood panels
Panel Opportunities - wood elevator cores
Opportunities – Hybrid Panels Hybrid Panel alternatives
Opportunities – Hybrid Panels Hybrid Panel alternatives
This concludes the:
American Ins3tute of Architects
Ontario Associa3on of Architects
Engineering Ins3tute of Canada
Con2nuing Educa2on Systems Program
Mee3ng 6 Storey Challenges with LSL
Weyerhaeuser – TrusJoist Engineered Lumber Products
www.woodbywy.com
Mississauga Office: 1-‐800-‐972-‐9663
Ques3ons/ Comments?