Low Pitch Roof Rafters

Structures such as sheds or barns can be frames with rafters every 24 again make sure to consult local codes.

Low pitch roof rafters.

After finding out your roof pitch angles you can use the calculator to perform the calculations for you instead of doing them manually. This horizontal load or thrust can be considerable especially on a low pitched roof. 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. Rafter span tables use these tables to determine lengths sizes and spacing of rafters based on a variety of factors such as species load grade spacing and pitch.

To resist thrust the irc calls for a structural ridge required for any roof with a pitch less than 3 12 or for each pair of rafters to be securely connected to each other by a continuous ceiling joist r802 3 2006 irc. This forms an angle of 18 5 between the horizontal section and the roof and creates a gentle incline that is seen as a midpoint between a low pitch and medium pitch roof. If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center. A 4 12 is a roof slope that rises by 4 inches for every 12 inches across.

It is always better to have a large rafter rather than be concerned with a sagging roof. The roof pitch calculator is a convenient online tool you can use to quickly assess the pitch of your roof to determine the length of rafters you need.