How Roof Pitch Affects Snow Load

Sloped roof snow loads are assumed to be acting on the horizontal projection of the surface.

How roof pitch affects snow load.

Roof pitch may have the most apparent effect on snow accumulation. There are a few things to consider when designing your steel building for a cold climate. A steel building with a high pitched roof will help clear snow and snow melt. Pitched roof snow load calculator ask local authorities about the maximum snow expected to fall in your town.

The weight of one foot of fresh snow ranges from 3 pounds per square foot psf for light dry snow to 21 psf for wet heavy snow. You can enter these values in any units you d like including meters and feet. 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. You need to supply the following information.

If unbalanced snow loading isn t required or specified the truss designer may enter the 25 psf snow load as a top chord live load tcll set the load duration factor to 1 15 for snow and turn snow loading off completely. Roof slope factor for multiple folded plate sawtooth and barrel vault roofs. To calculate the weight of snow on a roof use the first two sections of our snow load calculator. Even roofs that are pitched as low as 10 degrees have shown to shed snow and rain at least a little bit.

Multiple folded plate sawtooth or barrel vault roofs shall have a c s 1 0 with no reduction in snow load because of slope i e p s p f. Roof pitch is especially significant for snow. It s quite obvious that flat or low slope roofs will collect more snow than ones with a steep pitch. S 5 has updated the snow retention calculator to incorporate many new features including side by side comparisons for colorgard dualgard x gard 1 0 and x gard 2 0.

The sloped roof snow load is calculated using equation 7 4 1. When evaluating an existing roof for snow loads an engineer will want to know the year it was built the materials involved and the load the roof was designed to support to start. You may need to create a new login account to use the new calculator. If your roof is 1 000 square feet the total snow load is 15 000 pounds of snow.

When the roof slope is greater than 5 the roof is considered sloped. Or the 25 psf snow load could be entered as a roof snow load with the unbalanced snow loading option turned off. If your roof is pitched enter the length and width of the flat area covered by the roof. Length and width of your roof.

We re confident that our durable steel buildings can shoulder the load but accurate estimates and attention to detail will guarantee the safety of your steel building. Wind loads must also be considered in your steel building design. How much snow a roof can hold depends on the type of snow roofline and material among other considerations. P s c s p f.