Permanent Roof Truss Bracing

A project specific truss member permanent lateral restraint bracing design for the roof or floor framing structural system shall be permitted to be specified by the building designer or any registered design professional.

Permanent roof truss bracing.

Trusses which are not braced or which are not braced correctly are subject to toppling over or collapse. Building officials and inspectors have a veritable mountain of materials referenced by building codes. 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. Temporary installation restraint bracing consists of lateral restraint and diagonal bracing installed during construction for the purpose of holding trusses in their proper location.

Permanent bracing is intended to resist forces from gravity wind seismic and other loads. If trusses are not designed with stabilizer see bcsi 1 for stabilizer spacing and diagonal cross bracing required. 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. When if the cost of proper permanent bracing is included the overall cost of a roof truss installation will often be much greater than the installed cost quoted by builder or truss manufacturer.

Purlins 24 oc are typical along with the bottom bracing shown. If a specific truss member permanent bracing design for the roof or floor framing structural system is not provided by the owner or any building designer the method of permanent individual truss member restraint and diagonal bracing for the truss top chord bottom chord and web members shall be in accordance with bcsi b3 or bcsi b7. Truss clusters for maximum strength this image shows a cluster of three trusses tied together. Spacing wood blocking at odd spacings.

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. Flat coastal fringes fens airfields and moorland. Design professional to do the design for the temporary installation restraint and bracing and the permanent individual truss member restraint and bracing for trusses with clear spans of 60 or greater maximum spacing of tsbr spacer restraints on top chord per bcsi table b2 1 tsbr captures exact o c. In such cases bracing should be designed by an engineer in accordance with technical requirement r5.

Ground bracing not shown on either drawing is always. Many builders have not been properly installing permanent bracing for roof truss installations especially for relatively complicated roof geometries. Bracing of trusses is extremely important. Temporary bracing is bracing that is installed to hold the trusses true to line dimensions and plumb during the erection of the roof.