Pitch Of Roof For Snow

Intuitively this is the number of inches of snow on your roof in the place where the cover is the thickest.

Pitch of roof for snow.

In general determining the pitch of an existing roof is a simple calculation. A pitch over 9 12 is considered a steep slope roof between 2 12 and 4 12 is considered a low slope roof and less than 2 12 is considered a flat roof. Others allow a 1 4 inch slope. The chief reason for having a roof pitch is to redirect water and snow away from the roof and avoid any percolation that might result from stagnation of water on the roof.

The picture below shows the pitch of a 7 12 roof slope meaning that for 12 of horizontal measurement roof run the vertical measurement roof rise is 7. Importance of a roof pitch. 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. This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.

Some metal building manufacturers will not warranty a roof with a 1 4 inch slope. A 1 4 inch slope may work in alabama but one can expect leaks in minnesota or. Metal roofs leak under these circumstances. 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.

Low pitch roofs are easier to install and safer to walk around to complete repairs and maintenance. You can enter this value either as a ratio x 12 or as an angle whichever suits you better. In country with heavy snow and tough winter days the metal roof minimum slope is recommended to be 1 12. The minimum roof pitch is also subject to the standards set forth by the various building codes used in the respective regions.

This can be accomplished by measuring the number of inches the roof rises vertically for every 12 inches it extends horizontally. Low pitch roofs are seldom used in regions of severe weather due to the stress of snow accumulation on roofs of structures. When the snow piled up on the roof melting occurred and ice dams resulted in water ponding 3 inches deep. The table below shows common roof pitches and the equivalent grade degrees and radians for each.