BCSI’s Step-by-Step Truss Installation Process
An Overview | BCSI-B2
Prioritizing safety and a systematic approach in truss installation has many benefits to jobsite labor and long-term building performance. Here's an overview of several steps for a safe and sound truss installation process as contained in the Building Component Safety Information (BCSI) handbook. Future articles will explore and highlight key considerations within each step.
Step 1 | Establish Secure Ground Bracing
Establish a reliable exterior and interior ground bracing procedure. Proper bracing is the foundation of a project’s structural integrity.
Step 2 | Calculate On-Center Spacing
Determine the precise on-center spacing for top chord temporary lateral restraint (TCTLR) by referring to the table. Accurate spacing leads to a well-balanced build.
Maximum Top Chord Temporary Lateral Restraint (TCTLR) Spacing**
|Truss Span||TCTLR Max Spacing|
|Up to 30'||10' o.c.|
|30' - 45'||8' o.c.|
|45' - 60'||6' o.c.|
|60' - 80' *||4' o.c.|
|*Consult a Registered Design Professional for Trusses longer than 60'||**See BCSI-B10 For Trusses spaced greater than 2' o.c.,|
Step 3 | Securely Set the First Truss
Install the initial truss or gable end frame firmly by fastening it to ground bracing verticals. Make certain it's straight, in the right plane, and plumb, as it sets the template for the entire system. Avoid relying solely on end wall bracing, which is not recommended.
Step 4 | Safely Set Trusses 2 – 5
Position trusses 2 – 5 in line with TCTLR and ground bracing. Attach them securely at all bearing points, using shims when necessary. Exercise extreme caution to prevent premature truss release.
Step 5 | Add Top Chord Diagonal Bracing
Install top chord diagonal bracing or utilize structural sheathing for stability. This bracing is the key to stabilizing the first five trusses.
Step 6 | Stabilize with Web Member Diagonal Bracing
Add web member plane diagonal bracing to enhance stability in the first five trusses. Follow the recommended lateral restraint and diagonal bracing instructions in the building plans and reference BCSI guidelines.
Step 7 | Ensure Bottom Chord Stability
Establish stability for the bottom chord plane(s) by installing bottom chord temporary lateral restraint and diagonal bracing. Keep ground bracing in place until diagonal bracing and lateral restraints are installed for the first five trusses.
Step 8 | Repeat for Next Four Trusses
Continue the installation process by setting the next four trusses using TCTLR and replicate Steps 5 – 7.
Additional Steps | Repeat this sequence until all remaining trusses for the project are properly installed.
Refer back to these steps and/or BCSI, “Guide to Good Practices for Handling, Installing, Restraining & Bracing of Metal Plate Connected Wood Trusses,” to properly install all remaining trusses.
Again, future articles will look at each of these steps in greater depth, but hopefully this overview makes it clear that a systematic approach to truss installation is the best course to maintain a safe jobsite and a well-performing structure.