Minimum Roof Slope For Shingles

Determine the minimum slope of the roof based on the roofing material.

Minimum roof slope for shingles.

9 46 built up roof asphalt. What is the minimum slope for an asphalt shingle roof. Minimum required roof slope for roofing materials. The roof pitch between 2 12 and 4 12 is considered as a low pitch roof so shingles can be installed in the roof slope between 2 12 and 4 12.

Now lets get into the minimum roof slope requirements based on the. That works out to about nine degrees if that works better for you. So a 4 12 pitch roof rises 4 inches for every 12 inches of horizontal run. Minimum roof slopes required by roofing material requirements for roof coverings section r905.

This number corresponds to the number of inches of rise in a 12 foot run. The minimum requirement is 2 12. Roofing material or system. In 12 0 25 in 12 1 19 built up roof coal tar pitch.

In case a slope greater than this is necessary then a double underlayment application must be used as per the requirements of the international building code. Shingles of all types need to have a slope to function properly. Installation on roof slopes below a 2 in 12 pitch is not recommended at all. Why is 2 12 the minimum.

The minimum pitch for shingles is 1 6 which is equivalent to 4 inches rise to 24 inches run. There are differing opinions as to the minimum slope for a roof but the generally accepted minimum is 3 12. Asphalt shingles continue to be the most widely installed roof covering option in north america. Minimum pitch for corrugated metal roof.

18 43 asphalt shingles with special underlayment requirements 2 in 12. Minimum required slope x in 12 minimum required slope degrees asphalt shingles. Some people recommend not installing asphalt shingles on slopes below 5 12 but a skilled roofer may well be able to make this work. According to this code the minimum slope for asphalt shingles is 17 degrees or two vertical units to twelve units in the horizontal.

Pitch is measured in inches of vertical rise of the roof over one foot 12 inches of horizontal run. The 2 12 number is rise over run or two units of vertical for every 12 units horizontal. A shingle roof like this north dallas garage in the photo above may have a failure no matter how good a job the installer did. Considering the roof slope requirement is important.

The asphalt shingle manufactures recommend that you install asphalt shingles on a recommended minimum of 4 in 12 or greater however most manufactures will warrant their shingles down to a 2 in 12 pitch if the recommended installation method is used. They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends.