Roof Bracing Requirements

The ceiling joists restrain the exterior walls from being thrust outwards as gravity loads such as snow push down on the roof.

Roof bracing requirements.

The bracing described in this brochure covers both framed roofs and fully trussed roofs. This section requires trusses to be braced to prevent rotation and to provide lateral stability. Lower roof solution minimum of two braces are required for the lower storey roof but also a minimum of two per ridge line see figure 1. Truss web bracing is critical to the stability of the roof system yet very few residential projects have engineering observation of completed roof systems.

One roof brace is required per 50 m with a minimum of two per ridge line. Dormers porches do not require bracing. Roof braces can consist of either. Collar ties are required in the upper third of the roof system to provide restraint against the roof being pulled upward and outward from wind.

This is an area where the code requirements could be improved. One roof brace per 50m2 of roof area see rule 8 for minimum requirements one roof brace per 25m2 of roof area see rule 8 for minimum requirements 1. Unless the truss spans 60 feet or more special inspection of the truss web bracing installation is not required. Truss bracing requirements are found in section r802 10 3.

Roof planes less than 6m2 e g. If your local building authority has a rafter spacing code you may not space rafters wider than required by code. Rafter spacing rafters must be strong enough to hold the roof sheathing and the shingles. I roof plane brace or.