Weight Of Wet Snow On Roof

For any rafter the portion of the roof deck that transfers this load is the tributary area.

Weight of wet snow on roof.

This kind of snow will weigh around 7 pounds per cubic foot. Rain sleet and ice add to the weight of existing snow. Wind packed snow hard wind slab. 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.

Wet snow can be nearly three times heavier than dry fluffy snow. Wet snow dense sticky snow in relatively warm temperatures with little wind. Consider removing accumulated snow from your roof to avoid collapse. How much does snow weigh on a roof.

Fresh light and fluffy snow will weight much less than the dense packed or wet variety. 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. Snow which is just frozen ice crystals varies in weight by its volume and density. The roof deck collects the snow load and transfers the weight to the rafters.

So while a cubic foot of fresh powder might weigh in at 7 pounds that same amount of wet packed snow could be more like 20. 1 foot of snow on the roof 22 000 lbs 11 tons 20 psf 2 feet of snow on the roof. Good snow for making snowballs 1 75 lbs. Water weight is real.

28 40 light fluffy snow. 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 28 40 heavy wet snow. 21 85 25 6 lb ft 3. 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.

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. 17 25 lb ft 3. 0 27 0 40 g cm 3. 0 35 0 41 g cm.

On average two feet of snow can equal up to 19 tons of weight on your roof which can significantly weaken the structure. It is not advisable for a person to climb onto a snow or ice covered roof to remove accumulations.