Minimum Slope For Asphalt Shingles Roof

Shingles of all types need to have a slope to function properly.

Minimum slope for asphalt shingles roof.

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. Asphalt composition shingles are designed to be installed on roof slopes greater than a 4 in 12 pitch. There are differing opinions as to the minimum slope for a roof but the generally accepted minimum is 3 12. This means for every 12 horizontal units the roof must rise a minimum of 2 vertical units.

Asphalt shingles continue to be the most widely installed roof covering option in north america. That works out to about nine degrees if that works better for you. Roofing material or system. Asphalt shingles minimum roof slope roof pitch r905 2 2.

Some people recommend not installing asphalt shingles on slopes below 5 12 but a skilled roofer may well be able to make this work. Asphalt shingles can only be installed on roof slopes of 2 12 or greater. Minimum required slope x in 12 minimum required slope degrees asphalt shingles. The minimum requirement is 2 12.

In 12 0 25 in 12 1 19 built up roof coal tar pitch. What is the minimum pitch slope of an asphalt shingle roof. For example if it is a very low slope water including snowmelt or. 9 46 built up roof asphalt.

All asphalt shingle roofs with a pitch of 4 12 or more have an underlayment of 15 lb. Considering the roof slope requirement is important. The 2 12 number is rise over run or two units of vertical for every 12 units horizontal. 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.

For those who don t understand the roof pitch number here is a way to envision it. According to this code the minimum slope for asphalt shingles is 17 degrees or two vertical units to twelve units in the horizontal. Therefore the asphalt manufactures base their warranties around the minimum recommended pitch of 4 in 12. The requirements for an asphalt shingles roof are contained in the international building code.

Minimum required roof slope for roofing materials. 18 43 asphalt shingles with special underlayment requirements 2 in 12. Minimum slope for asphalt shingles. Asphalt felt paper that is tacked to the roof sheathing.

This number corresponds to the number of inches of rise in a 12 foot run. Why is 2 12 the minimum.