Roof Slope For Snow

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

Roof slope for snow.

They then have the option of putting dormers on the roof without damage to the valleys penetrations lower roofs and property below due to sliding snow and ice. If your roof is pitched enter the length and width of the flat area covered by the roof. At these slopes snow creeps rather than slides and is easy to manage. You can enter this value either as a ratio x 12 or as an angle whichever suits you better.

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. This allows the snow to stay on while venting the roof system. 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.

Roof slopes lower than 4 12 tend to perform well with metal roofs which are less prone to leakage and ice dam formation. Building a roof with wood shakes works well in moist colder climates as they don t dry out from the snow. For warm roofs c t 1 0 as determined from table e 3 with an unobstructed slippery surface that will allow snow to slide off the eaves the roof slope factor c s shall be determined using the dashed line in fig. On roof slopes between 4 12 and 6 12 rough textured roofing materials work best.