Minimum Angle For Roof Pitch

Divide the first part of the ratio by 12 to work out the pitch.

Minimum angle for roof pitch. The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles. Roof pitch and corresponding angles. 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. Pitch angle incline slope they all can be used to refer to the steepness of a roof.

This is the basis for calculating the angle which is approximately a 1 19 degree slope. This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement. What is the minimum slope for an asphalt shingle roof. The minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems.

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. Asphalt shingles continue to be the most widely installed roof covering option in north america. 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. To convert between american roofing ratios and pitch degrees follow these steps.

The recommended minimum roof pitch for shingles is 2 12 or simply two units of vertical rise to every twelve units of horizontal span. 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. They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends. The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run.

However you can only use this pitch with built up roofing or specialized synthetic roofing. A 12 12 pitch roof has a pitch angle of 45. This means if a roof rises 4 in the length of 12 your roof pitch would be 4 12 or 18 43 degrees. The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code.

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.