Install Roof Trusses

A. Finished-Project Specification

Scope: one completed truss-roof erection covering every common, girder, gable-end, attic, and valley-set truss shown on the placement diagram for the designated structure, with all specified temporary bracing removed only after permanent bracing and connectors are complete, and a signed truss-erection log with attached inspection results.

B. Required Documentation Schedule

Document	Source	Confirmation Required
Sealed truss design drawings	Truss designer / manufacturer	Current revision on site, sealed by the responsible engineer
Truss-placement diagram	Truss designer / supplier	Matches the delivered truss package and structure
Permanent-bracing information	Truss designer / manufacturer	Identifies all required web, chord, and lateral bracing
Connector schedule	Truss designer / connector manufacturer	Matches installed connector type and fastener requirements
Approved building plans	Design professional / plan set	Current revision, confirms structure is designed for trusses
Lift plan	General contractor / crane operator	Equipment, crew roles, exclusion zones, and wind limits confirmed

C. Erection Materials and Consumables

• Temporary-bracing lumber: sized and located per the truss documents or supplier's standard temporary-bracing detail; sufficient for continuous lateral restraint of every erected truss until permanent bracing is complete.
• Permanent-bracing material: type, size, and location specified by the truss documents.
• Truss connectors and fasteners: listed clips, ties, hangers, bolts, and straps matching the approved connector schedule; only listed fasteners for each connector.
• Documentation: one truss-erection log and inspection checklist per structure.

D. Acceptance Standards

Check	Standard
Truss identification and placement	Every truss matches its identification mark and location on the placement diagram; no substitutions
Spacing	Truss centers match the spacing specified on the placement diagram, held with approved gauges or spacers
Plumb	Each truss is plumb within the tolerance specified by the truss documents or design professional before permanent bracing is fastened
Bearing	Each truss is fully seated on its bearing wall or beam without twist or roll, matching the bearing condition shown on the truss drawings
Connectors	Type, quantity, fastener, and orientation match the approved connector schedule for every truss-to-wall and truss-to-truss connection
Temporary and permanent bracing	Temporary bracing is continuous and intact until permanent bracing shown on the truss documents is fully installed
Member condition	No truss member or metal connector plate is cut, drilled, notched, spliced, or altered in the field

E. Document Review and Delivery Inspection (Steps 1–5)

1. Obtain the sealed truss design drawings, truss-placement diagram, permanent-bracing information, connector schedule, handling instructions, and approved building plans. Confirm the revision date of each document against the project's document-control log before using it.
2. Confirm that the selected structure is designed for trusses and is separate from the site-built rafter project in Chapter 14. Verify against the approved building plans before any truss is staged.
3. Verify bearing walls, top plates, wall bracing, dimensions, truss supports, and lifting access. Confirm the wall system has passed the inspection required before truss loading and record the confirmation on the truss-erection log.
4. Inspect delivered trusses for identification, orientation, damage, broken plates, cuts, field alterations, and moisture exposure. Check each truss against its identification mark on the placement diagram as it is inspected.
5. Quarantine damaged or unidentified trusses and obtain manufacturer or engineer direction. Tag each quarantined truss, record its identification and defect, and do not stage it for erection until direction is received.

F. Staging and Layout (Steps 6–9)

1. Stage trusses upright or flat only as permitted by the supplier, with adequate support and restraint. Confirm the staging method matches the supplier's handling instructions before trusses are unloaded from the delivery vehicle.
2. Arrange trusses in installation order according to the placement diagram. Sequence the staged trusses so each is accessible in the order it will be lifted.
3. Mark truss centers on both bearing walls from a common reference point. Measure every truss-center mark from the same wall-top reference point identified in Section G below; do not measure sequentially from the previous mark.
4. Mark girder trusses, gable-end frames, attic trusses, valley sets, and special trusses by location. Label each special-truss location directly from the placement diagram and confirm it does not conflict with the common-truss layout.

G. Lift Planning and First-Truss Erection (Steps 10–12)

1. Review the lift plan, crane or mechanical equipment, tag lines, crew roles, exclusion zones, wind limits, and fall protection. Confirm every crew member's role and the location of the exclusion zone before the first lift.
2. Set the first truss at the designated location. Align the truss with its marked centerline and seat it fully on bearing before releasing rigging tension.
3. Plumb and brace the first truss using the approved temporary-bracing system. Install temporary bracing per the truss documents or supplier's standard detail before releasing the lifting equipment.

H. Sequential Erection and Restraint (Steps 13–16)

1. Set the second and subsequent trusses in the prescribed sequence. Follow the order established in Step 7 and confirm each truss's identification against the placement diagram before it is lifted.
2. Install continuous lateral restraint and diagonal bracing as trusses are erected. Do not allow any erected truss to stand without temporary lateral restraint, even briefly.
3. Maintain specified spacing using approved gauges or temporary spacers. Check spacing at both the top chord and bottom chord of each truss as it is set.
4. Seat each truss fully on bearing without twisting or rolling it. Verify full bearing contact and plumb before moving to the next truss.

I. Connectors and Permanent Bracing (Steps 17–20)

1. Install clips, ties, hangers, bolts, straps, or other connectors using listed fasteners. Match connector type, quantity, and orientation to the approved connector schedule for each truss-to-wall and truss-to-truss connection.
2. Install gable-end bracing and restraint according to the truss and building design. Complete gable-end vertical and lateral bracing before removing temporary bracing at that location.
3. Complete permanent web and chord bracing shown on the truss documents. Install every permanent brace shown on the truss drawings before releasing any corresponding temporary brace.
4. Do not cut, drill, notch, splice, or alter any truss member or metal plate. Refer any fit, damage, or conflict issue to the truss designer for a documented repair or modification detail.

J. Inspection and Documentation (Steps 21–24)

1. String and inspect truss peaks, heels, tails, and bearing lines. Sight along the string line and record any truss that deviates beyond the tolerance specified by the truss documents.
2. Verify truss identification, placement, spacing, plumb, bearing, connectors, temporary bracing, and permanent bracing. Complete the full acceptance-standards table in Section D for every truss before concealment.
3. Obtain repair details from the truss designer for any damage or installation conflict. Log the conflict, the date reported, and the party contacted; do not conceal the affected truss until direction is received.
4. Record truss documents, delivery condition, placement, connectors, repairs, and inspection results. Complete every required entry on the truss-erection log before roof sheathing begins.