Roof Slope For Snow

The steeper the pitch the better the snow will fall to the ground.

Roof slope for snow.

The slope that works best seems to be 5 12. Intuitively this is the number of inches of snow on your roof in the place where the cover is the thickest. On roof slopes between 4 12 and 6 12 rough textured roofing materials work best. Building a roof with wood shakes works well in moist colder climates as they don t dry out from the snow.

At these slopes snow creeps rather than slides and is easy to manage. 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. E 2a provided that for nonventilated warm roofs their thermal resistance r value equals or exceeds 30 ft 2 h f btu 5 3 c m 2 w and for warm ventilated roofs their r value equals or exceeds 20 ft 2 h f btu 3 5 cm 2 w. This allows the snow to stay on while venting the roof system.

You can enter this value either as a ratio x 12 or as an angle whichever suits you better. If your roof is pitched enter the length and width of the flat area covered by the roof. If you live in a climate with cold winters and numerous snow storms a pitched roof will prevent the snow from remaining on the top of your home. Roof slopes lower than 4 12 tend to perform well with metal roofs which are less prone to leakage and ice dam formation.