Roof Slope For Snow Load

Building a roof with wood shakes works well in moist colder climates as they don t dry out from the snow.

Roof slope for snow load.

When the roof slope is greater than 5 the roof is considered sloped. The primary reason is a fear of having the building collapse under a heavy snow load. If your roof is 1 000 square feet the total snow load is 15 000 pounds of snow. To figure out the load on your roof take the depth of snow in feet and multiply it by the weight of a cubic foot of snow.

The sloped roof snow load is calculated using equation 7 4 1. The sloped roof snow load p s shall be obtained by multiplying the flat roof snow load p f by the roof slope factor c s. Why do we design this way. 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.

Sloped roof snow loads are assumed to be acting on the horizontal projection of the surface. Our approach in north america is to use a metal roof with a steep slope that will allow the snow and ice to slide off. P s c s p f the thermal factor c t from table e 3 determines if a roof is cold or warm slippery surface values shall be used only where the roof s surface is unobstructed and sufficient space is available below the eaves to accept all the sliding snow. If the snow weighs 10 pounds per cubic foot and there are 1 5 feet on the roof each square foot of the roof is getting 15 pounds of pressure.

P s c s p f.