1 Presented by the Wood Truss Council of America
Permanent Bracing of Metal Plate Connected Wood Trusses
3 Overview of the Truss Industry Metal connector plate invented 1952
4 Overview of the Truss Industry Metal connector plate invented 1952
5 Overview of the Truss Industry Industry evolved
6 Overview of the Truss Industry Now $8 billion industry in the US World wide market
7 Overview of the Truss Industry Components for roofs, floors and walls
8 Residential
9 Residential
10 Multi-Family USDA Forest Products Lab
11 Wood American Forest & Paper Association 90% of residential framing
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
Wood Truss Standards National 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
Metal Connector Plates
Connector Plate Testing Develop proprietary plate values
Full Scale Truss Testing Verification of Design Methodology
Truss Design Process
Truss Layout Program
Truss Layout Program
Truss Layout Program
Truss Placement Plans
Truss Analysis Program
Truss Applications
Truss Floors
Truss Floors
3.9 Truss Roofs
Truss Roofs
Truss Job Site Package Truss design drawings
Truss Job Site Package Truss placement plan
Truss Job Site Package Handling, Installing & Bracing Guidelines
Truss Job Site Package Handling, Installing & Bracing Guidelines
Truss Job Site Package Handling, Installing & Bracing Guidelines
Truss Job Site Package Hanger details
Truss Long Term Storage Blocking to keep trusses off the ground
Truss Storage Conditions
39 < 6 inches 3.9 Truss Handling
Truss Handling Short Span < 30 ft
Truss Handling Short Span
Truss Handling Handling Medium Span < 60 ft
Truss Handling Medium Span
Truss Handling Handling Long Span > 60 ft
Truss Handling Long Span
Truss Ground Bracing Substantial bracing for first truss
Truss Bracing Lateral and Diagonal
Truss Bracing Short Pieces & Diagonal Bracing
Truss Bracing Sheathe Early & Often
Truss Bracing Pre-Assemble & Lift-in-place
Truss Bracing Results of Bad Bracing
Truss Bracing Results of Bad Bracing
Truss Bracing Results of Bad Bracing
Truss Bracing Results of Bad Bracing
Truss Bracing Results of Bad Bracing
Permanent Bracing Bottom Chord Plane Top Chord Plane Web Plane
Top Chord Bracing
Bottom Chord Bracing
Bottom Chord Bracing
Web Plane Bracing
Web Permanent Bracing Compression Web Bracing
Web Buckling
Web Bracing
Web Reinforcement BRACE WEB T-BRACE
Construction Loads
Construction Loads Never Stack Materials on Unbraced or Inadequately Braced Trusses
Construction Loads Never Stack an Unreasonable Amount of Material on the Trusses
Construction Loads Loads with No Bracing
Construction Loads Dangers of Overloading
70 Contents 1.0 Purpose of Bracing 2.0 Design Responsibilities 3.0 Design Information 4.0 Special Conditions 5.0 Diagonal Bracing 6.0 Top Chord Bracing 7.0 Bottom Chord Bracing 8.0 Summary
Guideline Document Commentary for Permanent Bracing of Metal Plate Connected Wood Trusses by John Meeks, P.E.
Loads in Plane
Lateral Loads WIND SEISMIC LOAD
Truss System Bracing
Truss Placement Plan
Quiz
Design Responsibilities 1.0 Purpose of Bracing 2.0 Design Responsibilities 3.0 Design Information 4.0 Special Conditions 5.0 Diagonal Bracing 6.0 Top Chord Bracing 7.0 Bottom Chord Bracing 8.0 Summary
2.1 Design Responsibilities Section 2.2 for Building Designer Responsibilities
Design Responsibilities ANSI/TPI/WTCA
Truss Designer
Component Design
Truss-to-Truss Connections
Permanent Web Bracing
Truss Submittal
Building Designer
Brace Design
Brace Load Transfer
Lateral Load Transfer
Ceiling Diaphragm
Roof Diaphragm
Truss-to-Girder Figure 1 from the Commentary
Truss-to-Bearing Figure 1 from the Commentary
Quiz
Design Information 1.0 Purpose of Bracing 2.0 Design Responsibilities 3.0 Design Information 4.0 Special Conditions 5.0 Diagonal Bracing 6.0 Top Chord Bracing 7.0 Bottom Chord Bracing 8.0 Summary
Truss Design Info
Bearing Info
Axial Forces
Quiz
Special Conditions 1.0 Purpose of Bracing 2.0 Design Responsibilities 3.0 Design Information 4.0 Special Conditions 5.0 Diagonal Bracing 6.0 Top Chord Bracing 7.0 Bottom Chord Bracing 8.0 Summary
Special Conditions System Bracing and Special Conditions on p.8
Horizontal Truss Figure 2 from the Commentary WIND
Horizontal Truss Figure 2 from the Commentary
Gable End Frame
Structural Gable End
Gable End Brace Location
106 Figure 3 from the Commentary 4.4 Gable End Brace Design Full depth Mid-depth
Reinforcement
108 Scab Reinforcement Reinforcement WEB Reinforcement WEB T-Reinforcement 4.5 Reinforcement Options Figure 4 Modified from the Commentary WEB L-Reinforcement Reinforcement Specially Designed Metal Reinforcement WEB Metal Reinforcement
Quiz
Diagonal Bracing 1.0 Purpose of Bracing 2.0 Design Responsibilities 3.0 Design Information 4.0 Special Conditions 5.0 Diagonal Bracing 6.0 Top Chord Bracing 7.0 Bottom Chord Bracing 8.0 Summary
Permanent Web Bracing
Location of Web Brace
Location of Web Brace
Diagonal Braces
Info on Diagonal Braces
Two Percent Rule
Spacing of Diagonal Bracing Procedure detailed in DSB-89: Recommended Design Specification for Temporary Bracing of Metal Plate Connected Wood Trusses Figure 5 from the Commentary
Bracing Minimums
Maximum L/d Ratio
System Sway HORIZONTAL FORCE
Sway Bracing < 4' oc Figure 6a from the Commentary
Sway Bracing Locations
Sway Bracing > 4' oc Figure 6b from the Commentary
Quiz
Top Chord Bracing 1.0 Purpose of Bracing 2.0 Design Responsibilities 3.0 Design Information 4.0 Special Conditions 5.0 Diagonal Bracing 6.0 Top Chord Bracing 7.0 Bottom Chord Bracing 8.0 Summary
Top Chord Bracing
Multi-piece Truss
Piggyback Assembly Supporting or Carrying Truss Supported or Cap Truss
Supporting Truss Top Chord spacing CLBs thickness
Supporting Truss Bracing Figure 7 from the Commentary
Bracing Options
Top Chord Extensions Structural Top Chord Extensions Figure 8a from the Commentary
Top Chord Filler Figure 8b from the Commentary Filler
Bottom Chord Filler Figure 9 from the Commentary Filler Bracing
Filler for Roof Slope Figure 10 from the Commentary Slope
Blocking for Top Chord
Valley Sets
Valley Framing
Valley Framing
Hip Trusses
Hip Truss Bracing Figure 12 from the Commentary Locations of CLBs
Mono Pitch Trusses LOAD Figure 13 from the Commentary
Top Chord Sheathing
Top Chord Purlins
Purlin Options Figure 14 from the Commentary
Roof Diaphragm Figure 15a from the Commentary
Roof Diaphragm Figure 15b from the Commentary
Quiz
Bottom Chord Bracing 1.0 Purpose of Bracing 2.0 Design Responsibilities 3.0 Design Information 4.0 Special Conditions 5.0 Diagonal Bracing 6.0 Top Chord Bracing 7.0 Bottom Chord Bracing 8.0 Summary
Bottom Chord Sheathing
Bracing also Required? Figure 16 from the Commentary Diagonal Bracing Continuous Lateral Bracing
Bracing Locations Diagonal Bracing Figure 16 from the Commentary
Special BC Bracing Cantilever
Special BC Bracing Multiple Bearing
Special BC Bracing Wind Uplift
Floor Truss Bracing Strongback bridging Deflection criteria above L/360 Deeper truss, Length/Depth=20 or less Figure 17 from the Commentary
Quiz
Summary 1.0 Purpose of Bracing 2.0 Design Responsibilities 3.0 Design Information 4.0 Special Conditions 5.0 Diagonal Bracing 6.0 Top Chord Bracing 7.0 Bottom Chord Bracing 8.0 Summary
Truss Member Bracing
Truss Designer Specifies web bracing location only
Building Designer Designs bracing system
Bracing Design Up to 4 ft o.c. 2x_ stress rated material Fasten with min. 2-16d common nails
Wide On Center Spacing
CLB Overlap
Floor Assemblies Strongbacks and ribbon band 10 ft o.c.
Quiz
167 WTCA is the Information Source
168 Structural Building Components Magazine
169
170 WTCA Homepage
171 ™ Wood Truss Council of America Phone