Minimum Roof Slope For Shingles

The 2 12 number is rise over run or two units of vertical for every 12 units horizontal.

Minimum roof slope for 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. Now lets get into the minimum roof slope requirements based on the. Minimum pitch for corrugated metal roof. This number corresponds to the number of inches of rise in a 12 foot run.

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. 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. Shingles of all types need to have a slope to function properly. Minimum required roof slope for roofing materials.

Minimum roof slopes required by roofing material requirements for roof coverings section r905. The minimum pitch for shingles is 1 6 which is equivalent to 4 inches rise to 24 inches run. So a 4 12 pitch roof rises 4 inches for every 12 inches of horizontal run. There are differing opinions as to the minimum slope for a roof but the generally accepted minimum is 3 12.

The minimum requirement is 2 12. That works out to about nine degrees if that works better for you. They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends. 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.

9 46 built up roof asphalt. According to this code the minimum slope for asphalt shingles is 17 degrees or two vertical units to twelve units in the horizontal. Determine the minimum slope of the roof based on the roofing material. What is the minimum slope for an asphalt shingle roof.

Minimum required slope x in 12 minimum required slope degrees asphalt shingles. 18 43 asphalt shingles with special underlayment requirements 2 in 12. Manufacturers of asphalt shingles recommend a pitch of 4 12 or more but the absolute minimum pitch is 2 12. Asphalt shingles continue to be the most widely installed roof covering option in north america.

Pitch is measured in inches of vertical rise of the roof over one foot 12 inches of horizontal run. Why is 2 12 the minimum. In 12 0 25 in 12 1 19 built up roof coal tar pitch. Roofing material or system.

The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles. Considering the roof slope requirement is important.