Pitched Roof Rafter Spacing

For pitched roofs flat roofs and ceiling joists.

Pitched roof rafter spacing.

The same concept holds true for roof trusses. Common spacing for trusses on this type of building is often between 2 and 4 feet but trusses built with advanced designs may allow spacing as great as 8 or 12 feet. An essential part of planning a patio roof or gazebo project is determining the number size and spacing of rafters beams and posts according to the loads they will carry. If your local building authority has a rafter spacing code you may not space rafters wider than required by code.

As a general rule roofs that have a high human occupancy rate should be framed with rafters every 16 structures such as sheds or barns can be frames with rafters every 24 again make sure to consult local codes. Visit the roof framing page for more information on cutting roof rafters and visit the roof pitch calculator for determining rafter lengths based on rise and run. Surveyors and structural engineers utilise data from tables below to help calculate the correct size strength and centres of roof timbers for the required spans and loadings. Rafters must be strong enough to hold the roof sheathing and the shingles.

Typical rafter spacing codes will specify a minimum spacing of 16 inches 19 2 inches or 24 inches. Surveyors span tables for designing roof rafters. Maximum rafter spans for a patio roof in areas with mild climates patio roofs are generally designed for loads of 30 psf pounds per square foot.