Roof Slope For Snow

Complete list of roofing types.

Roof slope for snow.

Flat roofs are common with industrial buildings boasting wide roof spans and are also popular in dry climates for houses where there is no need for the roof to help disperse rain and snow. Degrees to pitch rise in run table. Roof pitch multiplier table. Roof slopes are most commonly defined by the rise over run ratio.

This can be accomplished by measuring the number of inches the roof rises vertically for every 12 inches it extends horizontally. If your roof is pitched enter the length and width of the flat area covered by the roof. In general determining the pitch of an existing roof is a simple calculation. The minimum roof pitch for shedding snow is around 30 or a 6 12 or 7 12 slope although this is not a definite as the material of your roof the direction of the snow and wind are some factors that can affect whether or not snow will slide as roofs of as little as 10 have been reported to shed snow.

I e 4 inches of rise per 12 inches one foot of run. Even in these arid regions so called flat roofs are still installed with a slight pitch to keep water from pooling on top of the structure. If a roof slope rises say 4 inches when measured 12 inches along the bottom of a horizontal roof truss the roof slope is said to be 4 12. Intuitively this is the number of inches of snow on your roof in the place where the cover is the thickest.

Roof slope equivalents as rise. The key factors are usually snow loading requirements adequate slope and the use of snow guards when needed. In country with heavy snow and tough winter days the metal roof minimum slope is recommended to be 1 12. 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.

For example a roof with a 6 inch 12 pitch is one where it rises 6 inches vertically for every 12 inches of the horizontal run. They would say use a low slope approximately 5 12 and keep the snow on. What exactly is roof slope. Metal roofing systems have a good track record of performance in harsh winter environments as long as they are properly designed.

One key difference in industry s approach to snow on roofs is that keeping snow on the roof is something that they desire quite the opposite from the trend in north america.