Maximum Roof Pitch Angle

Roof pitch angle and slope factor charts.

Maximum roof pitch angle.

But the most commonly used pitches range between 4 12 and 9 12. In the usa the range of standard pitches is anywhere between 4 12 and 9 12. Carpenters frame rafters on an angle to pitch a roof. The combination of two numbers are used to display or show the roof pitch.

The roof pitch is important in determining the appropriate installation method and how much roofing material will be needed. You could also opt for a pvc flat roofing membrane. How do you calculate the slope of a roof. Roof pitch varies depending on culture climate style and available materials.

Pitches of less than 2 12 are considered flat roofs even though they may be very slightly angled. You write the pitch assuming a run of 12 inches thus the ratio would describe how much a roof rises for each foot of the run. As aforementioned there is no standard pitch of a roof. There is no standard universal roof pitch.

Pitches lower than 4 12 have a slight angle and they are defined as low slope roofs. Importance of a roof pitch. In the uk the typical house has a pitch between 40 50 although 45 should be avoided. Roof pitch or slope is a measure of vertical rise to horizontal run expressed in inches per foot.

Buffalo new york and montreal quebec canada specify 6 in 12 a pitch of approximately 26 6 degrees. Contemporary houses often have flat roofs which shouldn t be completely flat but should be around 1 40. This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement. Pitches above 9 12 are very highly angled and are designated steep slope roofs.

However you can only use this pitch with built up roofing or specialized synthetic roofing. The picture below shows the pitch of a 7 12 roof slope meaning that for 12 of horizontal measurement roof run the vertical measurement roof rise is 7. Gable and other multi pitched roofs allow for lower primary structures with a corresponding reduction in framing and sheathing materials. The chief reason for having a roof pitch is to redirect water and snow away from the roof and avoid any percolation that might result from stagnation of water on the roof.

Roof pitch is a term describing how steep or flat your roof slope is. Roof pitch is used to describe the slope or angle of the roof. The most commonly used roof pitches fall in a range between 4 12 and 9 12. The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run.

There are some standing seam metal roofing options available from atas and other manufacturers that can be installed on a roof with pitch of 1 12.