Min Roof Slope For Asphalt Shingles

Considering the roof slope requirement is important.

Min roof slope for asphalt shingles.

Therefore the asphalt manufactures base their warranties around the minimum recommended pitch of 4 in 12. Why is 2 12 the minimum. What is the minimum pitch slope of an asphalt shingle roof. Minimum required slope x in 12 minimum required slope degrees asphalt shingles.

This means for every 12 horizontal units the roof must rise a minimum of 2 vertical units. But shingle roofing is not watertight in the sense that standing water or wind driven water on a low slope roof can work its way up between the laps which is the reason for the minimum 2 12 slope. The requirements for an asphalt shingles roof are contained in the international building code. Asphalt shingles minimum roof slope roof pitch r905 2 2.

Minimum slope for asphalt shingles. Asphalt shingles continue to be the most widely installed roof covering option in north america. The minimum slope for an asphalt shingle roof is 2 12. They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends.

Asphalt composition shingles are designed to be installed on roof slopes greater than a 4 in 12 pitch. 18 43 asphalt shingles with special underlayment requirements 2 in 12. 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. According to this code the minimum slope for asphalt shingles is 17 degrees or two vertical units to twelve units in the horizontal.

The 2 12 number is rise over run or two units of vertical for every 12 units horizontal. Asphalt felt paper that is tacked to the roof sheathing. The minimum requirement is 2 12. 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. There are differing opinions as to the minimum slope for a roof but the generally accepted minimum is 3 12. For low slopes as well as any other slope your local building department should be contacted. 9 46 built up roof asphalt.

In 12 0 25 in 12 1 19 built up roof coal tar pitch. Shingles of all types need to have a slope to function properly. For example if it is a very low slope water including snowmelt or. This number corresponds to the number of inches of rise in a 12 foot run.

Some people recommend not installing asphalt shingles on slopes below 5 12 but a skilled roofer may well be able to make this work. A roof slope of 2 12 up to but not including 4 12 is considered as low in residential construction. What precautions need to be taken to install shingles on low slopes. For those who don t understand the roof pitch number here is a way to envision it.

That works out to about nine degrees if that works better for you. Minimum required roof slope for roofing materials.