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.

Low pitch roof rafters.

This horizontal load or thrust can be considerable especially on a low pitched 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. 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. Structures such as sheds or barns can be frames with rafters every 24 again make sure to consult local codes.

Many roofing shingles do not allow applications onto roofs at this 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. A 4 12 is a roof slope that rises by 4 inches for every 12 inches across. If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center.

More commonly roll on membranes such that use heat to bond seams together is used as a roofing material. 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.