Roof Truss Lateral Bracing

When truss spacing exceeds 2 feet purlins are generally required to support roof sheathing.

Roof truss lateral bracing.

Use wooden 2x4 or prefabricated metal braces as short member temporary lateral restraints between the trusses. Diagonal braces are required at each end of a truss row and repeated every 10 truss spaces 20 maximum. There are two separate types of bracing to be concerned about. Individual truss member lateral restraint and diagonal bracing the truss designer identifies the location of required individual truss member i e web top chord or bottom chord restraint bracing.

7 2 9 bracing for trussed rafter roofs trussed rafters shall be suitably braced to support applied loads and self weight without undue movement. Certain truss members require bracing in order to carry the full design load. Permanent bracing listed on the truss design drawing for specific web members and permanent bracing for the roof or floor system. Purlins 24 oc are typical along with the bottom bracing shown.

Flat coastal fringes fens airfields and moorland. For the purposes of this chapter the guidance and use of standard trussed rafter bracing does not apply to homes on or near exposed sites e g. To strengthen the roof system truss clustering cross bracing and wind bracing is recommended at both end of the buildings and every 20 for longer span buildings. Hold these restraints in place with two nails each.

Type of load important. Set each truss after the first with its top chord temporary lateral restraint aligned with the ground bracing. This bracing serves the purpose of preventing out of plane buckling due to the applied loads shown on the truss design drawing. If trusses are not designed with stabilizer see bcsi 1 for stabilizer spacing and diagonal cross bracing required.

The stabilizer must be supplemented with diagonal bracing in the roof and ceiling planes and cross bracing in the web plane at required intervals shown on the individual truss design drawing tdd. This condition generally applies when trusses are spaced at 2 feet.