Roof Slope For Snow Load

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.

Roof slope for snow load.

If your roof is 1 000 square feet the total snow load is 15 000 pounds of snow. 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. 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.

P s c s p f. When the roof slope is greater than 5 the roof is considered sloped. Why do we design this way. The primary reason is a fear of having the building collapse under a heavy snow load.

As i design roofs today in ski resort areas i use one of the above types of roofs and plan to keep the snow on. The steeper the pitch the better the snow will fall to the ground. Building a roof with wood shakes works well in moist colder climates as they don t dry out from the 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.

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.