Two feet of snow on a roof with a footprint of say 28 40 feet could weigh 45 000 pounds.
Snow on roof weight distribution.
Per square foot of roof space so anything more than 2 feet of snow could be too much for your roof to handle.
On multiple factors including.
For ground snow loads greater than 20 pounds per square foot the roof load is equal to.
Once you know these values our snow load calculator automatically finds the total weight of snow on your roof.
How much snow can a roof hold.
It is determined based.
Importance occupancy and use of the building.
When designing and building a new roof you should give consideration to any face of the of the home that s going to be sheltered from the wind or precipitation as this can impact the distribution of roof snow load as it accumulates.
Ground snow load value.
It could weigh over 20 pounds if it s wet and compacted.
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.
Additionally if snow falls unevenly on the roof then of course the weight distribution of the accumulation is going to be uneven which poses and even greater risk.
Snow load thickness density.
If you want to calculate these values by hand use the following formulas.
That s more than 22 tons.
Per square foot of roof space which is beyond the typical snow load capacity of most roofs.
Where snow isn t a problem the live load can come from people working on the roof and any equipment they take on to the.
Only one inch of ice weighs in at just under five pounds per square foot almost five times an average snow s weight.
One inch of snow may weigh anywhere from one quarter pound per square foot to one and three quarter pounds per square foot.
Wind exposure of roof.
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.
For roofs that are flat and with ground snow loads lower than 20 pounds per square foot the roof snow load is equal to 70 of the product of the exposure thermal and importance factors and the ground snow load.
3 5 inches of old snow is equal to one inch of water or about 5 lbs.
Roof snow load is defined as the weight of snow on the roof surface used in design of the building structure ibc 2012.
Wet snow can be nearly three times heavier than dry fluffy snow.
You can also find the load per square meter or square foot of roofing by opening the advanced mode.
Two feet of old snow and two feet of new snow could weigh as much as 60 lbs.
Step 4 determine the flat roof snow load.
A cubic foot of snow can weigh about 7 pounds if it s dry and fluffy.
On average two feet of snow can equal up to 19 tons of weight on your roof which can significantly weaken the structure.
