# What kind of load is snow on a roof?

## What kind of load is snow on a roof?

Snow load is the downward force on a building’s roof by the weight of accumulated snow and ice. The roof or the entire structure can fail if the snow load exceeds the weight the building was designed to shoulder. Or if the building was poorly designed or constructed. It doesn’t take a blizzard to cause problems.

How do you calculate roof 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. 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.

In general, roof snow loads are somewhere between 50-90% of the ground snow load, depending on the exposure and heat transfer.

### Can too much snow damage roof?

The weight of snow and ice As weightless as snowflakes seem, combined into a layer of snow, they are heavy and can cause your roof to fail. The damage ranges from leaks to broken shingles and even roof collapse.

How do you calculate snow load on a roof?

5-20 for light snow

• 20-40 for packed snow
• 40-58 for packed snow with ice
• 58 for ice
• How to calculate roof snow loads?

– Type A: warm roof, slippery unobstructed surface: Y = 5 – Type B: warm roof, other surface: Y = 30 – Type C: cold roof, slippery unobstructed surface: Y = 15 – Type D: cold roof, other surface: Y = 45