17 25 lb ft 3.
Weight of wet snow on roof.
Compacted snow after prolonged and heavy wind exposure 1 98 lbs.
If the snow is dense and wet however a cubic foot.
Wet snow dense sticky snow in relatively warm temperatures with little wind.
Wind packed snow hard wind slab.
Snow which is just frozen ice crystals varies in weight by its volume and density.
0 27 0 40 g cm 3.
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 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.
Dry fluffy snow is the least concern with respect to 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.
Wet snow can be nearly three times heavier than dry fluffy snow.
The roof deck collects the snow load and transfers the weight to the rafters.
It is not advisable for a person to climb onto a snow or ice covered roof to remove accumulations.
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.
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.
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.
This kind of snow will weigh around 7 pounds per cubic foot.
Fresh light and fluffy snow will weight much less than the dense packed or wet variety.
How much does snow weigh on a roof.
28 40 light fluffy snow.
Water weight is real.
For any rafter the portion of the roof deck that transfers this load is the tributary area.
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.
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.