Minimum Slope For Asphalt Shingles Roof

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

Minimum slope for asphalt shingles roof.

They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends. Asphalt shingles can only be installed on roof slopes of 2 12 or greater. Why is 2 12 the minimum. Minimum slope for asphalt shingles.

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 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. This means for every 12 horizontal units the roof must rise a minimum of 2 vertical units. All asphalt shingle roofs with a pitch of 4 12 or more have an underlayment of 15 lb.

Minimum required slope x in 12 minimum required slope degrees asphalt shingles. Shingles of all types need to have a slope to function properly. This number corresponds to the number of inches of rise in a 12 foot run. Asphalt felt paper that is tacked to the roof sheathing.

Considering the roof slope requirement is important. Asphalt shingles minimum roof slope roof pitch r905 2 2. Roofing material or system. 9 46 built up roof asphalt.

The minimum requirement is 2 12. In 12 0 25 in 12 1 19 built up roof coal tar pitch. There are differing opinions as to the minimum slope for a roof but the generally accepted minimum is 3 12. Asphalt composition shingles are designed to be installed on roof slopes greater than a 4 in 12 pitch.

What is the minimum pitch slope of an asphalt shingle roof. 18 43 asphalt shingles with special underlayment requirements 2 in 12. For example if it is a very low slope water including snowmelt or. Some people recommend not installing asphalt shingles on slopes below 5 12 but a skilled roofer may well be able to make this work.

The requirements for an asphalt shingles roof are contained in the international building code. That works out to about nine degrees if that works better for you. Therefore the asphalt manufactures base their warranties around the minimum recommended pitch of 4 in 12. For those who don t understand the roof pitch number here is a way to envision it.

The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles. According to this code the minimum slope for asphalt shingles is 17 degrees or two vertical units to twelve units in the horizontal.