Minimum Roof Pitch For Snow Loads

When the roof slope is greater than 5 the roof is considered sloped.

Minimum roof pitch for snow loads.

Roof design snow loads derived from figure 321 02 of the wisconsin. Begin by measuring 12 inches on your level and marking it with a pencil. The key factors are usually snow loading requirements adequate slope and the use of snow guards when needed. The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code.

A minimum slope of 1 inch per foot is recommended in snow country. All commercial buildings and structures should use the ground snow load values from the 2009 ibc and not the residential design values given below. Sloped roof snow loads are assumed to be acting on the horizontal projection of the surface. The sloped roof snow load is calculated using equation 7 4 1.

The minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems. If you are adding an addition to your home or installing skylights knowing the existing pitch is important. Metal roofing systems have a good track record of performance in harsh winter environments as long as they are properly designed. 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.