Minimum Angle For Roof Pitch

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.

Minimum angle for roof pitch.

The minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems. This means if a roof rises 4 in the length of 12 your roof pitch would be 4 12 or 18 43 degrees. However it is regrettable that many installers usually ignore this requirement due to the desire for a quick installation process. The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles.

To convert between american roofing ratios and pitch degrees follow these steps. On blue prints architects engineers usually display the pitch of a roof in the format shown on the image where number 4 represents a rise and number 12 represents a length. Divide the first part of the ratio by 12 to work out the pitch. Roof pitch and corresponding angles.

Roof pitch refers to the measurement of the slope of a roof and you express this as a ratio. Flat roof slope minimum according to the international building code the typical built up flat roof that uses tar or asphalt goes by the guideline that for every foot 12 inches of a flat roof a minimum of inch must step up or down. Although there s isn t any standard pitch of a roof used on all kinds of sloped roofs you can determine the range of pitches by using a roof angle calculator and by considering factors like the local climate and roofing materials. This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.

The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run. In the roofing trade the go to term is pitch and it is expressed in terms of 12 inches so the pitch of a roof is determined by how many inches the slope rises for every 12 inches it runs horizontally. The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code. A 12 12 pitch roof has a pitch angle of 45.

Find the inverse tangent of the pitch to find the angle in degrees. They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends. However you can only use this pitch with built up roofing or specialized synthetic roofing. Asphalt shingles continue to be the most widely installed roof covering option in north america.

This is the basis for calculating the angle which is approximately a 1 19 degree slope.