Permanent Roof Truss Bracing

Trusses which are not braced or which are not braced correctly are subject to toppling over or collapse.

Permanent roof truss bracing.

Temporary installation restraint bracing consists of lateral restraint and diagonal bracing installed during construction for the purpose of holding trusses in their proper location. 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. 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. It is very important that the contractor or homeowner responsible for truss erection read through all documents inside the job packet.

Bracing provides stability against unintended movement or motion. If trusses are not designed with stabilizer see bcsi 1 for stabilizer spacing and diagonal cross bracing required. Building officials and inspectors have a veritable mountain of materials referenced by building codes. Bracing of trusses is extremely important.

Many builders have not been properly installing permanent bracing for roof truss installations especially for relatively complicated roof geometries. Permanent bracing is intended to resist forces from gravity wind seismic and other loads. Temporary bracing is bracing that is installed to hold the trusses true to line dimensions and plumb during the erection of the roof. 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.

Ground bracing not shown on either drawing is always. Purlins 24 oc are typical along with the bottom bracing shown. 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. Truss clusters for maximum strength this image shows a cluster of three trusses tied together.

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. In such cases bracing should be designed by an engineer in accordance with technical requirement r5. Spacing wood blocking at odd spacings. In addition temporary bracing holds the trusses in a stable condition until permanent truss bracing and other permanent components such as roof and floor sheathing joist or purlins which contribute to the overall rigidity of the roof or floor are in place.