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:bryan@apawood.orgWebsite:www.apawood.org

704 877 6255Email: bruce@woodworks.orgWebsite:www.woodworks.orgwww.woodworks.org