1 Presented by the Wood Truss Council of America

1

Presented by thePresented by the

Wood Truss Council of America Wood Truss Council of America

Permanent BracingPermanent Bracing

of Metal Plate Connected of Metal Plate Connected

Wood TrussesWood Trusses

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Overview of the Truss IndustryOverview of the Truss Industry

Metal connector plate invented 1952

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Metal connector plate invented 1952

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Industry evolved

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Now $8 billion industry in the US World wide market

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Components for roofs, floors and walls

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ResidentialResidential

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ResidentialResidential

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Multi-FamilyMulti-Family

USDA Forest Products LabUSDA Forest Products Lab

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WoodWood

American Forest & Paper AssociationAmerican Forest & Paper Association

90% of residential framing

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3.9 Wood Trusses3.9 Wood Trusses Heavy timber truss

bolt or split ring connected Plywood gusset truss

Post WW-II construction Metal truss plate invented in 50’s Today major EWP component

Residential 62%, Multifamily 64% roof market share

Residential 15%, Multifamily 26% floor market share

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3.9 Wood Truss Standards3.9 Wood Truss StandardsNational Design Standard for Metal

Plate Connected Wood Truss Construction ANSI/TPI 1 – 1995

National Standard and Recommended Guidelines on Responsibilities for Construction Using Metal Plate Connected Wood Trusses ANSI/TPI/WTCA 4 - 2002

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3.9 Metal Connector Plates3.9 Metal Connector Plates

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3.9 Connector Plate Testing3.9 Connector Plate Testing

Develop proprietary plate values

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3.9 Full Scale Truss Testing3.9 Full Scale Truss TestingVerification of Design Methodology

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3.9 Truss Design Process3.9 Truss Design Process

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3.9 Truss Layout Program3.9 Truss Layout Program

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3.9 Truss Placement Plans3.9 Truss Placement Plans

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3.9 Truss Analysis Program3.9 Truss Analysis Program

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3.9 Truss Applications3.9 Truss Applications

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3.9 Truss Floors3.9 Truss Floors

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3.9 Truss Floors3.9 Truss Floors

3.9 Truss Roofs3.9 Truss Roofs



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3.9 Truss Job Site Package3.9 Truss Job Site PackageTruss design drawings

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3.9 Truss Job Site Package3.9 Truss Job Site PackageTruss placement plan

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3.9 Truss Job Site Package3.9 Truss Job Site PackageHandling, Installing & Bracing Guidelines

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3.9 Truss Job Site Package3.9 Truss Job Site PackageHanger details

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3.9 Truss Long Term Storage3.9 Truss Long Term Storage Blocking to keep trusses off the ground

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3.9 Truss Storage Conditions3.9 Truss Storage Conditions

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< 6 inches

3.9 Truss Handling3.9 Truss Handling

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3.9 Truss Handling3.9 Truss HandlingShort Span < 30 ft

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3.9 Truss Handling3.9 Truss HandlingShort Span

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3.9 Truss Handling3.9 Truss HandlingHandling Medium Span < 60 ft

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3.9 Truss Handling3.9 Truss HandlingMedium Span

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3.9 Truss Handling3.9 Truss HandlingHandling Long Span > 60 ft

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3.9 Truss Handling3.9 Truss HandlingLong Span

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3.9 Truss Ground Bracing3.9 Truss Ground BracingSubstantial bracing for first truss

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3.9 Truss Bracing3.9 Truss BracingLateral and Diagonal

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3.9 Truss Bracing3.9 Truss BracingShort Pieces & Diagonal Bracing

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3.9 Truss Bracing3.9 Truss BracingSheathe Early & Often

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3.9 Truss Bracing3.9 Truss BracingPre-Assemble & Lift-in-place

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3.9 Truss Bracing3.9 Truss BracingResults of Bad Bracing

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3.9 Permanent Bracing3.9 Permanent Bracing

Bottom Chord PlaneBottom Chord Plane

Top Chord PlaneTop Chord Plane

Web PlaneWeb Plane

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3.9 Top Chord Bracing3.9 Top Chord Bracing

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3.9 Bottom Chord Bracing3.9 Bottom Chord Bracing

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3.9 Bottom Chord Bracing3.9 Bottom Chord Bracing

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3.9 Web Plane Bracing3.9 Web Plane Bracing

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3.9 Web Permanent Bracing3.9 Web Permanent Bracing

Compression Web BracingCompression Web Bracing

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3.9 Web Buckling3.9 Web Buckling

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3.9 Web Bracing3.9 Web Bracing

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3.9 Web Reinforcement3.9 Web ReinforcementBRACE

WEB

T-BRACET-BRACE

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3.9 Construction Loads 3.9 Construction Loads

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3.9 Construction Loads3.9 Construction LoadsNever Stack Materials on Unbraced or

Inadequately Braced Trusses

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3.9 Construction Loads3.9 Construction LoadsNever Stack an Unreasonable Amount

of Material on the Trusses

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3.9 Construction Loads3.9 Construction LoadsLoads with No Bracing

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3.9 Construction Loads3.9 Construction LoadsDangers of Overloading

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ContentsContents1.0 Purpose of Bracing2.0 Design Responsibilities3.0 Design Information4.0 Special Conditions5.0 Diagonal Bracing6.0 Top Chord Bracing7.0 Bottom Chord Bracing8.0 Summary

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1.1 Guideline Document1.1 Guideline DocumentCommentary for Permanent Bracing of Metal Plate Connected Wood Trusses

by John Meeks, P.E.

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1.2 Loads in Plane1.2 Loads in Plane

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1.3 Lateral Loads1.3 Lateral Loads

WIND SEISMIC

LO

AD

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1.4 Truss System Bracing1.4 Truss System Bracing

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1.5 Truss Placement Plan1.5 Truss Placement Plan

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1.0 Quiz1.0 Quiz

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2.0 Design Responsibilities2.0 Design Responsibilities1.0 Purpose of Bracing2.0 Design Responsibilities3.0 Design Information4.0 Special Conditions5.0 Diagonal Bracing6.0 Top Chord Bracing7.0 Bottom Chord Bracing8.0 Summary

2.1 Design Responsibilities2.1 Design Responsibilities

Section 2.2 for Building Designer Responsibilities

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2.1 Design Responsibilities2.1 Design ResponsibilitiesANSI/TPI/WTCA 4-2002

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2.2 Truss Designer2.2 Truss Designer

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2.2 Component Design2.2 Component Design

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2.2 Truss-to-Truss Connections2.2 Truss-to-Truss Connections

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2.2 Permanent Web Bracing2.2 Permanent Web Bracing

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2.2 Truss Submittal2.2 Truss Submittal

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2.3 Building Designer2.3 Building Designer

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2.3 Brace Design2.3 Brace Design

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2.3 Brace Load Transfer2.3 Brace Load Transfer

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2.3 Lateral Load Transfer2.3 Lateral Load Transfer

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2.3 Ceiling Diaphragm2.3 Ceiling Diaphragm

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2.3 Roof Diaphragm2.3 Roof Diaphragm

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2.4 Truss-to-Girder2.4 Truss-to-Girder

Figure 1 from the Commentary

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2.4 Truss-to-Bearing2.4 Truss-to-Bearing


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2.0 Quiz2.0 Quiz

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3.0 Design Information3.0 Design Information1.0 Purpose of Bracing2.0 Design Responsibilities3.0 Design Information4.0 Special Conditions5.0 Diagonal Bracing6.0 Top Chord Bracing7.0 Bottom Chord Bracing8.0 Summary

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3.1 Truss Design Info3.1 Truss Design Info

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3.2 Bearing Info3.2 Bearing Info

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3.3 Axial Forces3.3 Axial Forces

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3.0 Quiz3.0 Quiz

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4.0 Special Conditions4.0 Special Conditions1.0 Purpose of Bracing2.0 Design Responsibilities3.0 Design Information4.0 Special Conditions5.0 Diagonal Bracing6.0 Top Chord Bracing7.0 Bottom Chord Bracing8.0 Summary

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4.0 Special Conditions4.0 Special Conditions System Bracing and

Special Conditions on p.8

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4.1 Horizontal Truss4.1 Horizontal Truss


WIND

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4.1 Horizontal Truss4.1 Horizontal Truss


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4.2 Gable End Frame4.2 Gable End Frame

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4.2 Structural Gable End4.2 Structural Gable End

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4.3 Gable End Brace Location4.3 Gable End Brace Location

106Figure 3 from the Commentary

4.4 Gable End Brace Design4.4 Gable End Brace Design

Full depth

Mid-depth

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4.5 Reinforcement4.5 Reinforcement

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Scab Reinforcement

Reinforcement

WEB

Reinforcement

WEB

T-Reinforcement

4.5 Reinforcement Options4.5 Reinforcement Options

Figure 4 Modified from the Commentary

WEB

L-Reinforcement

Reinforcement

SpeciallyDesigned MetalReinforcement

WEB

Metal Reinforcement

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4.0 Quiz4.0 Quiz

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5.0 Diagonal Bracing5.0 Diagonal Bracing1.0 Purpose of Bracing2.0 Design Responsibilities3.0 Design Information4.0 Special Conditions5.0 Diagonal Bracing6.0 Top Chord Bracing7.0 Bottom Chord Bracing8.0 Summary

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5.1 Permanent Web Bracing5.1 Permanent Web Bracing

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5.1 Location of Web Brace5.1 Location of Web Brace

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5.1 Location of Web Brace5.1 Location of Web Brace

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5.1 Diagonal Braces5.1 Diagonal Braces

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5.1 Info on Diagonal Braces5.1 Info on Diagonal Braces

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5.2 Two Percent Rule5.2 Two Percent Rule

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5.3 Spacing of Diagonal Bracing5.3 Spacing of Diagonal Bracing

Procedure detailed in DSB-89: Recommended Design Specificationfor Temporary Bracing of Metal Plate Connected Wood Trusses


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5.4 Bracing Minimums5.4 Bracing Minimums

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5.5 Maximum L/d Ratio5.5 Maximum L/d Ratio

805.1120

dL

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5.6 System Sway5.6 System Sway

HORIZONTALFORCE

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5.7 Sway Bracing 5.7 Sway Bracing << 4' oc 4' oc

Figure 6a from the Commentary

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5.7 Sway Bracing Locations5.7 Sway Bracing Locations

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5.7 Sway Bracing > 4' oc5.7 Sway Bracing > 4' oc

Figure 6b from the Commentary

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5.0 Quiz5.0 Quiz

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6.0 Top Chord Bracing6.0 Top Chord Bracing1.0 Purpose of Bracing2.0 Design Responsibilities3.0 Design Information4.0 Special Conditions5.0 Diagonal Bracing6.0 Top Chord Bracing7.0 Bottom Chord Bracing8.0 Summary

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6.0 Top Chord Bracing6.0 Top Chord Bracing

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6.1 Multi-piece Truss6.1 Multi-piece Truss

ft 13Height Max.

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6.1 Piggyback Assembly6.1 Piggyback Assembly

Supporting or Carrying Truss

Supported or Cap Truss

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6.1 Supporting Truss Top Chord6.1 Supporting Truss Top Chord

spacing

CLBsthickness

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6.1 Supporting Truss Bracing6.1 Supporting Truss Bracing


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6.1 Bracing Options6.1 Bracing Options

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6.2 Top Chord Extensions6.2 Top Chord Extensions

StructuralTop Chord Extensions


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6.3 Top Chord Filler6.3 Top Chord Filler


Filler

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6.4 Bottom Chord Filler6.4 Bottom Chord Filler


Filler

Bracing

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6.5 Filler for Roof Slope6.5 Filler for Roof Slope


Slope

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6.5 Blocking for Top Chord6.5 Blocking for Top Chord

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6.6 Valley Sets6.6 Valley Sets

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6.6 Valley Framing6.6 Valley Framing

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6.6 Valley Framing6.6 Valley Framing

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6.7 Hip Trusses6.7 Hip Trusses

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6.7 Hip Truss Bracing6.7 Hip Truss Bracing


Locations of CLBs

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6.8 Mono Pitch Trusses6.8 Mono Pitch Trusses

LOAD


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6.9 Top Chord Sheathing6.9 Top Chord Sheathing

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6.10 Top Chord Purlins6.10 Top Chord Purlins

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6.10 Purlin Options6.10 Purlin Options


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6.0 Quiz6.0 Quiz

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7.0 Bottom Chord Bracing7.0 Bottom Chord Bracing1.0 Purpose of Bracing2.0 Design Responsibilities3.0 Design Information4.0 Special Conditions5.0 Diagonal Bracing6.0 Top Chord Bracing7.0 Bottom Chord Bracing8.0 Summary

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7.1 Bottom Chord Sheathing7.1 Bottom Chord Sheathing

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7.2 Bracing also Required?7.2 Bracing also Required?


Diagonal Bracing

ContinuousLateralBracing

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7.3 Bracing Locations7.3 Bracing Locations

80dL that so Designer Trussby S, Spacing,

Diagonal Bracing


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7.4 Special BC Bracing7.4 Special BC Bracing

Cantilever

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Multiple Bearing

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Wind Uplift

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7.5 Floor Truss Bracing7.5 Floor Truss Bracing

Strongback bridgingDeflection criteria above L/360Deeper truss, Length/Depth=20 or less


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7.0 Quiz7.0 Quiz

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8.0 Summary8.0 Summary1.0 Purpose of Bracing2.0 Design Responsibilities3.0 Design Information4.0 Special Conditions5.0 Diagonal Bracing6.0 Top Chord Bracing7.0 Bottom Chord Bracing8.0 Summary

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8.1 Truss Member Bracing8.1 Truss Member Bracing

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8.2 Truss Designer8.2 Truss DesignerSpecifies web bracing location only

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8.3 Building Designer 8.3 Building Designer Designs bracing system

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8.4 Bracing Design8.4 Bracing DesignUp to 4 ft o.c.2x_ stress rated materialFasten with min. 2-16d common nails

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8.5 Wide On Center Spacing8.5 Wide On Center Spacing

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8.6 CLB Overlap8.6 CLB Overlap

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8.7 Floor Assemblies8.7 Floor AssembliesStrongbacks and ribbon band

10 ft o.c.

10 ft o.c.

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8.0 Quiz8.0 Quiz

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WTCA is the Information SourceWTCA is the Information Source

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Structural Building Components Structural Building Components MagazineMagazine

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www.woodtruss.comwww.woodtruss.com

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WTCA HomepageWTCA Homepage

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™

Wood Truss Council of AmericaWood Truss Council of America

Email [email protected]

Phone 608-274-4849

mailto:[email protected]

Documents

1 Presented by the Wood Truss Council of America