Scribd
Upload
24 views1 page

Bracing Web

This document provides guidance on standard bracing details for roof structures. It outlines different types of bracing including rafter diagonal bracing to provide lateral stability, longitudinal bracing at each joint to provide stability to truss nodes, and chevron bracing for larger roof profiles. Restraining battens are also described to provide lateral restraint to web members. Important notes are made that the bracing only provides adequate restraint if building regulation criteria are fully met, and common breaches like unbuttressed wall lengths or heights need to be considered in design.

Uploaded by

David O'Meara
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
24 views1 page

Bracing Web

This document provides guidance on standard bracing details for roof structures. It outlines different types of bracing including rafter diagonal bracing to provide lateral stability, longitudinal bracing at each joint to provide stability to truss nodes, and chevron bracing for larger roof profiles. Restraining battens are also described to provide lateral restraint to web members. Important notes are made that the bracing only provides adequate restraint if building regulation criteria are fully met, and common breaches like unbuttressed wall lengths or heights need to be considered in design.

Uploaded by

David O'Meara
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
You are on page 1/ 1

Standard Bracing Detail

All permanent bracing should be a minimum size of 22mm x 97mm or 38mm x 89mm. The
timber should be free of major strength reducing defects. Timber bracing should be fixed using
two 3.35mm diameter galvanized round wire nails at each crossover point. The length of the
nails should be 65mm for 22/25mm bracing and 75mm for 38mm bracing.

The main types of bracing include: -

RAFTER DIAGONAL BRACING (RD). This is bracing fixed to the underside of the rafter, it
provides lateral stability to the roof structure and in conjunction with the total roof diaphragm,
transfers wind loads to shear resisting walls.

LONGITUDINAL BRACING (LR/LT/LTB). This is bracing fixed at each joint excluding


support locations. It acts in conjunction with the rafter diagonal bracing to provide lateral
stability to the roof structure and provides essential stability to the truss nodes used in the
structural analysis.

CHEVRON BRACING (CB). This is diagonal bracing fixed to internal members. It provides
additional stability to the complete roof system. Such bracing is required on duo-pitch roof
profiles in excess of 8 metres and for mono-pitched roof profiles in excess of 5 metres.

RESTRAINING BATTENS (RB). These are longitudinal braces fixed to web members to
provide lateral restraint to those members.

The following points of interest from BS5268: part 3 are worth of a note.

The bracing shown is that for truss stability only, which means that it will only provide
adequate restraint for the structure if the criteria within Appendix A of the building regulations
are fulfilled completely It should be noted that common breaches of the requirements are: -
unbuttressed wall length exceeding 9 metres; wall heights exceeding 2.6 metres; the omission
of plasterboard to the ceiling and truss rafters being spaced further apart than 600mm centres.
It is essential that these important construction details, among others, are considered carefully
before completion of the building design.

You might also like