Engineered Wood BeamsWhat Today’s Designers Need to Know
P B Li d / B R dli P EPresenters: Bruce Lindsey / Bryan Readling, P.E.
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 y greported 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 anyendorsement 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 thematerials, methods, and services will be addressed at the conclusion of this presentation. Registration no. 08S04.
Learning Objectives
•Compare an array of generic and proprietary engineered wood beams and select thewood beams and select the best product for a given application.• Understand common mis-applications for engineeredapplications for engineered wood beams that affect their performance with regard to strength• Examine both proper and i ti ti fimproper connection options for transferring loads within Engineered Wood Beam systems..•Determine proper comparison•Determine proper comparison and specification of Engineered Wood Beam products in unique structural applications based on completed structural examples.
Agenda:
• Products & Applications
Glulam, LVL, PSL, LSL, I‐Joist (as a beam)
• Applications
Exposure Types and Usep yp
Treatments
• Connections
Mechanical ConnectionsMechanical Connections
Pre‐Engineered Connections
• Case Studies
• Environmental Benefits
GlulamGlulam
Gl lGl lGlulamGlulam
GlulamGlulam
Features & ApplicationsFeatures & Applications
Glulam:• Wood laminations bonded t thtogether• Wood grain runs parallel to the length
Typical Widths:• 2-1/2" to 10-3/4"
Laminations:1-3/8" for Southern Pine1-1/2" for Douglas Fir
Dispersal of Strength Reducing CharacteristicsDispersal of Strength Reducing Characteristics Stock Beam
CamberCamber
Z CZ C bbZero CZero Camberamber
Glulam CamberGlulam Camber
L = Span (ft)
TOP
Δ = Camber (in)
Radius of Curvature (ft)
GlulamGlulam
ManufacturingManufacturing
L = Span (ft)Stock Manufactured RadiusRadius
Douglas Fir : 3500’ radius
Δ = Camber (in)
Southern Pine: 2000’ radius
( )Radius of Curvature (ft)
Custom Glulam Beam ManufacturingCustom Glulam Beam Manufacturing
Tennis Courts, Aurora, CO
Engineered Lay‐ups
Compression zone
Inner zone
Tension zone
Critical Tension Zone
Tension zone
Critical Tension Zone
GlulamGlulam
ManufacturingManufacturing
BalancedContinuous Spans or Cantilevered
UnbalancedSimple Spans
Engineered Engineered LayupsLayups
Continuous Spans or CantileveredSimple Spans
TOP No. 2DNo. 2No 2
No. 2No 2
TL
No. 2
No. 3
No. 2
No. 3
No. 2No 1
No. 3
No. 2No 1
TLNo. 1
TL=Tension Lamination
TLNo. 1
Lamination
GlulamGlulam
ManufacturingManufacturingEngineered Engineered LayupsLayups
Simple Span – Unbalanced Layup
Cantilever or Continuous Span Cantilever or Continuous Span
“TOP” or “Arriba” Stamp Improperly Installed Unbalanced Glulam
Common Glulam Depths
Species will determine depthsDF is manufactured in 1-1/2” laminations while SP is planed down to 1-3/8” laminations.
SP (1-3/8”)6-7/8”8-1/4”
DF (1-1/2”)6”
7-1/2”9-5/8”
11”12-3/8”13 3/ ”
9”10-1/2”
12”13 1/2”13-3/4”
15-1/8”16-1/2”
Etc
13-1/2”15”
16-1/2”EtcEtc. Etc.
I‐Joist Compatible (IJC) Depths
9 1/2"Common
9‐1/2"
11‐7/8"I-Joist Compatible Depths:
14"
16"
Depths:
9-1/2”11 7/8” 1611-7/814”16”
Innovation:Gl l i h LVL T i L i tiGlulam with LVL Tension Lamination
LVL Tension Lam
•Full length- noFull length no finger joints
•Greater tensile•Greater tensile strength = 3000 psip
Glulam Floor Beams Glulam Floor Beams -- EWS C415EWS C415
Glulam Appearance ClassificationsGlulam Appearance Classifications
F i (F i L)Framing (Framing‐L)(full width‐ i.e. 3‐1/2", 5‐1/2”)
Industrial (Industrial‐L)(planed each side‐ i.e. 3‐1/8”, 5‐1/8”)
Architectural (sanded / filled after planing/ eased edges)(sanded / filled after planing/ eased edges)
Premium (verify local availability)
Appearance classifications do not affect design values.affect design values.
Stock Glulam Specifications
Common Species:Common Species:Douglas Fir or Southern Pine
Stock Glulam Properties:2400 Fb 1 8E2400 Fb 1.8E
High Strength Glulam Properties:3000Fb 2 1E3000Fb 2.1E
Glulam Grading Agencies
Both Agencies adhere to the gANSI-A190 standards.
Additional information at:Additional information at:www.aitc-glulam.organd
dwww.apawood.org
StrengthStrength
Gl lam High a Bridge Hiroshima JapanGlulam Highway Bridge – Hiroshima, JapanGlulam trusses are 10’ deep with 200’+ spans
Dimensional Stability
Waterproof adhesives eliminate glue line degradation in exposed structures
Custom Laminated Glulams
Disney Ice Center – Anaheim, CA
High Strength of Glulam
Glulams are spaced 22’ o.c. and span 116’
Laminated Veneer Lumber (LVL)
Uniform, consistent beam that can be field connected to achieve desired width and load capacitiescapacities.
Common lengths il bl t 48’ iavailable up to 48’ in
depths ranging from 5-1/2” to 24”.
LVLLVL
Features & ApplicationsFeatures & Applications
Laminated Veneer Lumber (LVL):• Produced by bonding thin veneerstogethertogether
• Used for studs, beams, headers, rafters &scaffold planking
The grain of all veneers is gparallel to the long direction
LVL Manufacturing
Logs are peeled into veneer sheets which are sorted by grade then laminated together to form homogeneous billet ofhomogeneous billet of laminated veneers.
Billets are cut to length then rip cut to desiredthen rip cut to desired plank width.
LVLLVL
Sizes and SpecificationsSizes and Specifications
•Commonly available up to 48’ in length•Depending upon thickness, up to four separate pieces may be nailed bolted orseparate pieces may be nailed, bolted or screwed together to achieve desired width or load capacity. (always follow manufacturer’s connection guidelines).manufacturer s connection guidelines).
Common Thicknesses:• 3/4" to 3-1/2“•Typical width 1-3/4”
Common Depths:• 3-1/2” to 24”
LVL Floor Beams LVL Used in Floor Opening
Parallel Strand Lumber (PSL) PSL ManufacturingPSL Manufacturing
Parallel Strand Lumber (PSL):Manufactured from veneers clipped into long strands in a parallel formation and bondedparallel formation and bonded together
Strand length‐to‐thickness ratio is garound 300
Strand construction allows for b i l ili ibetter raw material utilization and the use of various wood species.
PSL Features & BenefitsPSL Features & Benefits
Parallel Strand Lumber (PSL):Single piece install without field connections to establish width.
f d d d fUse of stranded veneer instead of full sheet veneers allows the use of smaller diameter trees and/or different wood species in manufacturing.
O i i i llOpen grain composition allows for unique face finish options when visually exposed.
PSL Sizes & SpecificationsPSL Sizes & Specifications
Parallel Strand Lumber (PSL):High Strength, uniformly constructed beam typically used for beam header or columnfor beam, header, or column material.
Stock widths: 2‐11/16”, 3‐1/2”, 5‐1/4”, and 7”.
Stock Depths: 9‐1/4”, 9‐1/2”, 11 1/4” 11 7/8” 14” 16” 18”11‐1/4”, 11‐7/8”, 14”, 16”, 18”
2.0E (beams) & 1.8E (columns)
L th t 48’Lengths up to 48’
Laminated Strand Lumber (LSL) LSL ManufacturingLSL Manufacturing
Laminated Strand Lumber (LSL)
Similar to PSL.Flaked strand length-to-thickness ratio is around 150thickness ratio is around 150Used for a variety of applications from studs toapplications from studs to millwork components
LSL Features & BenefitsLSL Features & Benefits
Laminated Strand LumberLaminated Strand Lumber (LSL):
• Dimensionally stable replacementDimensionally stable replacement for most lumber framing
•Cost effective alternative to expensive light-gauge framing.
• Can be manufactured in a variety of sizes and shapes.
•One piece LSL headers offer simplified framing and red ced laborsimplified framing and reduced labor costs in field.
LSL Sizes & SpecificationsLSL Sizes & Specifications
Laminated Strand Lumber (LSL):
Common widths:1‐1/2”, 3‐1/2”, 5‐1/4”
Common Depths3‐1/2”, 5‐1/2”, 7‐1/4”, 9‐1/2”
Design Properties vary byDesign Properties vary by manufacturer
Common Lengthsgup to 24’
I‐Joist (used as a beam or header) II‐‐Joist as a BeamJoist as a Beam
ManufacturingManufacturing
I-Joist:• Commonly used for floor and roof framing
L l th dil il bl• Long lengths readily available
Flange Widths:
Flange:• Lumber• LVL g
• 1-1/2" to 3-1/2"
Common Depths:• 9-1/2"
• LSL
9 1/2• 11-7/8"• 14"• 16"
Web:• OSB•Plywood
Bending Force in FlangesBending Force in Flanges
Uniform Load
CompressionCompression
Tension
CForces are Max. at LLC
L
Engineering 101Engineering 101Engineering 101Engineering 101
Shear Force in WebShear Force in WebShear Force in WebShear Force in Web
Uniform Load
Collected Shear (Vertical) Force is Max. At SupportLC
Collected Shear (Vertical) Force is Max. At Support
Engineering 101Engineering 101Engineering 101Engineering 101
Double I‐Joist DetailConsult with the I-Joist manufacturer’s specifications for properspecifications for proper blocking materials and nailing patterns
Typical 1/8" Gap betweenbetween blocking and flange
ALL Double I-Joists must be properly sistered with solidsistered with solid blocking in between the webs.
Additional details and information available on APA Form Z725.
Fire Considerations
Fire Considerations Fire Considerations
IBC Section 602.4 – Type IV Construction (Heavy Timber)
Solid or Glue Laminated Timber Minimum Cross Section (nominal)Floor Column - 8” minimum in any directionRoof Column - 6” x 8” minimum Floor Beam – 6” wide x 10” deep minimumFloor Arch/Truss Components – 8” minimum in any directionRoof Arch / Truss / Beams – Consult with IBC Section 602.4.3
Sizes from 4”x6” to 6”x 8” depending upon bearing height and shape of component / beam.
Fire Rated Glulam
AITC Technical Note #7: Calculation of Fire ResistanceCalculation of Fire Resistance of Glued Laminated Timberwww.aitc-glulam.org
AF&PA Technical Report #10: Calculating the Fire Resistance of Exposed Wood MembersMemberswww.awc.org
APA Technical Note #EWS Y245B: Calculating Fire Resistance of Glulam Beams and Columnswww apawood orgwww.apawood.org
Wet use Exposure
GlulamsGlulams(Decay resistant Species and Pressure Treated)
PSL(Pressure Treated)
Wet use Exposure: PSL
Preservative Treated PSL
•Provides resistance to both decay and insects.
• Cost effective alternative to high cost steel members for exterior deck or roof support.exterior deck or roof support.
• Allows longer spans within design when replacing built-up treated lumber beams, reducing foundation costs and expanding design options.
Wet use Exposure: PSL
Manufacturing
•Wood Species mix is adapted in manufacturing to ensure treatment penetration andtreatment penetration and retention
• Pre-treatment manufacturedPre treatment manufactured size adjusted to allow for expansion of product after treatment.
• Kiln Dried after treatment to ensure dimensional stability.
Treated PSL Sizes and Specifications
Common Beam Widths:3-1/2”, 5-1/4”
Common Beam Depths:9-1/4”, 11-7/8”, 14”, 16”
Common Column Sizes:3-1/2” x 5-1/4”5-1/4” x 5-1/4”5 1/4 x 5 1/47” x 7”
Consult manufacturer for proper wet use factors and structural design properties.
Wet use Exposure: GlulamPreservative Treated Glulam
•Provides resistance to both•Provides resistance to both decay and insects.
•Variety of species andVariety of species and treatment chemical options available (varies by location and manufacturer)
• Sizing options (width & depth) beyond common treated PSL sizes.
•Best choice for visually exposed applicationsexposed applications.
Preservative Treated Glulam Manufacturing
•Wet-use adhesives are utilized during lamination process.
•Pressure Treatment occurs after laminating andafter laminating and machining of product at mill.
•Some western speciesSome western species such as Douglas Fir require incising (see photo) to ensure proper penetration of p p ptreatment.
•Kiln Drying after treatment varies by manufacturer.
Preservative Treated Glulam Sizes and Specifications
Common Sizes:Varies by manufacturer –C ti l i i t i lCross sectional size is typical to that of untreated glulam but length is usually limited to contracted treatment facilitycontracted treatment facility capacity.
Design Properties:Design Properties:Vary by species and level of treatment. Consult with manufacturer’s specifications.
Glulam Glulam –– Decay Resistant SpeciesDecay Resistant Species
Alternatives to Preservative Treatment:
• Alaska Yellow Cedar
• Western Red Cedar
• Port Orford Cedar
Connecting Wood
Wood likes to take on load spread over its surfaceWood likes to take on load spread over its surface
Concentrated at a single fastener –wood is more prone to split and crush Connecting Wood
Mechanical fasteners– Keep ‘em small
– Use lots of themUse lots of them
– Keep scale of fastener small relative to woodsmall relative to wood member
Tension Perpendicular to Grain
Wood splits from:• notchesnotches• hanging loads• restraint by connector
Notching
Problem SolutionTension perpendicularTension perpendicularto grain
Connecting Wood
Wood, like other materials, moves in varying environments
Design Considerations• End restraint conditions:
– Simple span has 2 supportsp p pp
– Continuous has 3 or more supports
– Cantilevered has 1 supportpp
– Supports may be beams, columns, walls…
ContinuousSimple
Cantilevered
Field Notching and Drilling of Laminated Field Notching and Drilling of Laminated Field Notching and Drilling of Laminated Field Notching and Drilling of Laminated Veneer Lumber (Tech Note EWS G535)Veneer Lumber (Tech Note EWS G535)
Permissible Holes for LVL
2” h l di t Minimum amount of spacing= 2 x diameter of the largest hole
• 2” max. hole diameter• 3 holes max.
1/31/31/3
d1/3
1/3 span 1/3 span 1/3 span
Zone where holes are permitted for passage of wires, conduits, etc.
p p p
Excessive NotchingExcessive Notching
Right WrongRight Wrong
Field Notching and Drilling of Glued Field Notching and Drilling of Glued g gg gLaminated Timber Beams Laminated Timber Beams
-- Tech Note EWS S560Tech Note EWS S560
Notching Creates Tension Notching Creates Tension Perpendicular Perpendicular t th it th i
Notching Creates Tension Notching Creates Tension Perpendicular Perpendicular t th it th ito the grainto the grain
Max. LVL end notch = 0.10dMax. LVL end notch = 0.10d
to the grainto the grain
Max. LVL end notch = 0.10dMax. LVL end notch = 0.10d
Pre‐engineered Connectors
Joist and beam hangers
• Top and face mountop a d ace ou t• Product specific• Use correct nail• Fill all holes• Ensure proper p pfastener penetration
Generic NDS Connectors
Ti b i tTimber rivets
Source: ClevelandSteel.com
Timber Rivet System
timber rivet cross section
Generic NDS Connectors
Split rings & Shear Plates
Source: ClevelandSteel.com
Specialized Connectors
Shear platesLoosely fitting in groove
Easy connection to steel
Used in pairs for wood‐to‐wood connectionsconnections
Bolt assists in load transfertransfer
Specialized Connectors
Split ringsSplit rings
Tightly fitting in groove
More prone to shrinkage splits
Bolt does not assist in load transfer
TopTop--Loaded LVLLoaded LVLTopTop--Loaded LVLLoaded LVL SideSide--Loaded LVLLoaded LVLSideSide--Loaded LVLLoaded LVL
Proprietary Connections
Multi‐ply linear members and inter‐ply shear/load transferp y p y /
Mechanical Connections
Larger fastenersBolts in wood bearing are limited to 1 inch diameter or lessBolts in wood bearing are limited to 1 inch diameter or less
Mechanical Connections – Group Action Geometry Factor, CΔ
Spacing, End, & Edge Distancesp g, , g
Parallel to grain
Restraint by Connector
Full‐depth side plates– May cause splitting– May cause splitting
– Restrains wood shrinkage
Starlight TheaterRockford ILRockford, IL
Before
Splits
After Beam to Concrete
Beam on shelf– Prevent contact with concrete
Beam to Masonry
Application– Bearing plate under beam to prevent contact with masonry
– Need 1/2” air gap between wood and masonry
Connection Serviceability
Protect end‐grain and gconnection
Preservative treated or decay‐resistant species
end caps and flashingend caps and flashing
For More Information…
on I‐joists and Laminated Beams
• Go to: www.apawood.org• Click: publications• Search for:
– Builder Tips: Storage, Handling & Safety Recommendations f APA P f R d I J ifor APA Performance Rated I‐Joists
– Builder Tips: Stairwell Openings Parallel to I‐Joist Floor FramingEngineered Wood Construction Guide: Guide to Engineered– Engineered Wood Construction Guide: Guide to Engineered Wood Products
– APA Performance Rated I‐Joists– EWS Data File: Shear Transfer at Engineered Wood FloorsEWS Data File: Shear Transfer at Engineered Wood Floors
The Beauty of Glulams
Arched Glulams24F-V5, 8-3/4” x 50-7/8” section75-foot radius22 feet on center116 foot spanspMoment splices used to allow for transportation
Disney Ice
Beaverton, OR Library
26-foot tall Glulam Trees
• 3/4” DF• 3/4 DF laminations
• 28 feet on center• “Branches”
support 5-1/8”xsupport 5-1/8 x 12” glulam purlins
Glued Laminated Decking Roof
Solid Purlins
Diagonal Glulams
Gl l P li @ 14Glulam Purlins @ 14 feet o.c.
Building Size: 69 000 sqft69,000 sqft
Cost: $175/sf
Wisconsin Visitors Information Center
Wisconsin Visitors Information Center
Welcoming Arch
SYP Glulam Trussesspan 32 feet100 feet 5-1/2” x 11-1/2”Glulam BeamsGlulam Beams450 feet 5-1/2 x 7-1/2” Glulam
PurlinsCost - $100 / sf
Showcasing Engineered Wood Products
REI Flagship Store‐ SeattleEnvironmentally
Conscious Building Materials
Glulams:Roof Trusses & Purlins
Floor Beams
External Columns & Beams
Stair TreadsStair Treads
Plywood:Roof, Floor & Wall SheathingSheathing
OSB:Wall finish material w/ stainstain
Investco Financial Corporation22-foot tall interior shear walls
Birch Veneer Plywood
Cost Effective: $16.28/sf`(interior build out)
2/3 l h2/3 less than avg.
Engineered Wood In School Design
Cost Competitive
Construction Cost Savings
Roof Insulation
Life-Cycle Value
Durability
$115/sf – Liberty HS, Bakersfield
Dining Hall & Admin. Bldg.
Eleanor Roosevelt College, UCSD
UCSD Dining Hall 2010 Vancouver Olympics
RichmondRichmond Olympic Oval
completed 2008
Richmond Olympic Oval
330’ A h330’ Arches –Wood/Steel C itComposite
Richmond Olympic Oval
330’ Arches – House Mech./Elec.
Case Studies
UniqueUniqueUnique Unique ApplicationsApplicationsApplicationsApplications
Reser oir Co erReser oir Co erReservoir CoverReservoir CoverVan Norman Bypass Reservoir Cover:yp
Protecting the water supply for the City of LA665,000 sq ft roof covering 15 acres665,000 sq ft roof covering 15 acresCompleted in 10 weeks
Unique Applications
•Alaskan Yellow C d Gl lCedar Glulams-naturally decay resistant
•No chemical treatmentstreatments
•Concrete lcolumns on a
60’x60’ grid
Unique Applications
Corrosive Mineral Storage
One of Oregon’s Largest Wood Buildings:Choices – stainless steel / 3-step epoxy painted steelChoices stainless steel / 3 step epoxy painted steel100 glulam arch members – 8-3/4”x 55-1/2”x 115’ Erection crew never exceeded 20 persons
The Cathedral of Christ the Light
Oakland, CA
The Cathedral of Christ the Light
Wood is Renewable
In North America we plant about 3 million trees ‐ every day *
Growth now exceeds harvest by more than 25% *
* Source: U.S. Forest Service
A Model of Sustainability and Green Building
From 1953 to 1997From 1953 to 1997
• Forest inventories grew 36% *
• Over 50 million• Over 50 million wood‐frame homes were builthomes were built
* Source: U.S. Forest Service
Questions?Questions?Please contact us:Please contact us:Please contact us:Please contact us:
Bryan Readling, P.E.S i Fi ld E i
Bruce LindseySenior Field EngineerAPAPhone:704-661-9718
Technical DirectorWoodworks SoutheastPhone:704-877-6255
Email:[email protected]:www.apawood.org
704 877 6255Email: [email protected]:www.woodworks.orgwww.woodworks.org