Minimum Roof Slope For Snow

Minimum required roof slope for roofing materials.

Minimum roof slope for snow.

Metal roofing systems have a good track record of performance in harsh winter environments as long as they are properly designed. In 12 0 25 in 12 1 19 built up roof coal tar pitch. Roofing material or system. If you are adding an addition to your home or installing skylights knowing the existing pitch is important.

On roof slopes between 4 12 and 6 12 rough textured roofing materials work best. The key factors are usually snow loading requirements adequate slope and the use of snow guards when needed. Determine the minimum slope of the roof based on the roofing material. A minimum slope of 1 inch per foot is recommended in snow country.

18 43 asphalt shingles with special underlayment requirements 2 in 12. In country with heavy snow and tough winter days the metal roof minimum slope is recommended to be 1 12. According to this code the minimum slope for asphalt shingles is 17 degrees or two vertical units to twelve units in the horizontal. They hold the snow in place and keep it from accumulating and then sliding off in large slabs that can be dangerous.

There are some opinions that standing seam metal roof minimum slope is 12 but it increases the possibility of leaking on the few first days of snow arrival. If your roof is pitched enter the length and width of the flat area covered by the roof. Begin by measuring 12 inches on your level and marking it with a pencil. People have been killed by snow avalanches sliding off roofs during big snow winters.

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. The minimum pitch for shingles is 1 6 which is equivalent to 4 inches rise to 24 inches run. Minimum required slope x in 12 minimum required slope degrees asphalt shingles. 9 46 built up roof asphalt.

You can enter this value either as a ratio x 12 or as an angle whichever suits you better.