Snow On Roof Weight

Snow loading is the downward force exerted on structures by the weight of accumulated snow.

Snow on roof weight.

Calculating the weight of snow is useful when you need to know the total weight it adds for example to calculate the weight on a roof. The roof of any building is the area subject to the greatest weight temperature and moisture extremes. S 1 25 p where s is the number of inches of snow on your roof and p is the pounds per square foot of that snow. 28 40 light fluffy snow.

Consider removing accumulated snow from your roof to avoid collapse. The roof deck collects the snow load and transfers the weight to the rafters. For in depth information on this topic please see the links available on our page snow issues and roofs. Fresh light and fluffy snow will weight much less than the dense packed or wet variety.

Snow which is just frozen ice crystals varies in weight by its volume and density. But usually the buildings that are collapsing from snow are usually outbuildings with flat roofs and collapse due to. Psf pounds per square foot. If you live in the us our snow load calculator compares the total weight on your roof with the permissible load calculated according to the standards issued by the american society of civil engineers regarding the minimum design loads for buildings and other structures asce7 16.

On average two feet of snow can equal up to 19 tons of weight on your roof which can significantly weaken the structure. For any rafter the portion of the roof deck that transfers this load is the tributary area. 1 foot of snow on the roof 8 000 lbs 4 tons 7 psf 2 feet of snow on the roof 16 000 lbs 8 tons 14 psf 3 feet of snow on the roof 24 000 lbs 12 tons 21 psf. Here are a few examples of the weight of snow on a roof.

How much does snow weigh on a roof. It is also important to remember that that math doesn t take into account any ice you have on your roof which weighs much more than heavy wet snow weighs. A roof in an older building may be underbuilt and therefore more vulnerable to structural problems. The critical factor with the roof collapsing and damaging is the weight of the snow and not the depth of the snow on your roof.

For an average size roof about 2000 square feet covered in heavy wet snow a good rule of thumb is the weight of one compact suv 3 470 lbs on your roof for every 1 inch of snow.