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.

Minimum roof slope for snow.

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. Determine the minimum slope of the roof based on the roofing material. Minimum pitch for corrugated metal roof. 18 43 asphalt shingles with special underlayment requirements 2 in 12.

The key factors are usually snow loading requirements adequate slope and the use of snow guards when needed. Intuitively this is the number of inches of snow on your roof in the place where the cover is the thickest. People have been killed by snow avalanches sliding off roofs during big snow winters. 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.

According to this code the minimum slope for asphalt shingles is 17 degrees or two vertical units to twelve units in the horizontal. Begin by measuring 12 inches on your level and marking it with a pencil. Roofing material or system. In country with heavy snow and tough winter days the metal roof minimum slope is recommended to be 1 12.

You can safely measure the roof pitch from inside your attic with a level that is either 18 or 24 inches a tape measure and a pencil. The minimum pitch for shingles is 1 6 which is equivalent to 4 inches rise to 24 inches run. If you are adding an addition to your home or installing skylights knowing the existing pitch is important. You can enter this value either as a ratio x 12 or as an angle whichever suits you better.

They hold the snow in place and keep it from accumulating and then sliding off in large slabs that can be dangerous. Minimum required roof slope for roofing materials. 9 46 built up roof asphalt. In 12 0 25 in 12 1 19 built up roof coal tar pitch.

A minimum slope of 1 inch per foot is recommended in snow country.