How Much Snow On Roof Is Too Much

The drifts on the roof were 5 feet deep.

How much snow on roof is too much.

According to the national research council of canada a roof should be able to withstand pressure of at least 21 pounds per square foot psf this number can fluctuate based on regional building regulations but any well built roof should be able to sustain this much weight before it gets too stressed. Building codes in your area require that roofs be built to withstand reasonable natural elements in your area so as long as your roof was. What precautions can i take to avoid too much snow on the roof. According to this houselogic article it s not how much snow we got a foot at our place but the weight of the snow that we need to worry about.

For the twin cities metro area the roof snow load equals 35 pounds per square foot or 7 x 50. But as the chart below shows packed snow with ice can easily overload a roof once it reaches about 12 off depth. As it turns out while this latest blast from old man winter did dump a lot of snow on us it s probably not too much for most residential structures here in southeast minnesota. Considering the snow type even more than the buildup depth is critical when assessing the state of the snow on your roof.

As everyone knows cold fluffy snow is very light while wet snow can be extremely heavy. Last winter we had snow on the ground that was up to our hips. A depth of more than 30 cm of snow may be greater than your roof can support. This is based on the approximate measure of a cubic foot of snow having a mass of 10 pounds.

You have probably heard of or seen the difference between wet snow and fluffy snow. The chart below courtesy of paul schimnowski p e gives some examples of snow loads. 7 5 to 12 5 cm 3 to 5 in of old snow is equivalent to 2 5 cm 1 in of water or about 2 3 kg 5 pounds per square foot of roof space. Two feet or more of old.

Most roof designs can handle snow loads of 20 40 lbs per square foot. Six inches of wet snow is the same weight as 38 inches of dry snow. Wet snow weighs considerably more than dry or fluffy snow because as you can probably guess water weighs more than air. So how much snow does this equal.

How to protect your roof watch for ice build up on the edge and valleys of your roof. How much snow is too much for a roof to handle. One of the major determining factors for how much snow is too much for your roof is how heavy the snow fall is.