Snow On Roof Weight Distribution

The live load on a roof is the weight of any temporary objects on the roof.

Snow on roof weight distribution.

It could weigh over 20 pounds if it s wet and compacted. For ground snow loads greater than 20 pounds per square foot the roof load is equal to. 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. On multiple factors including.

Snow load thickness density. Per square foot of roof space which is beyond the typical snow load capacity of most roofs. If you want to calculate these values by hand use the following formulas. 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.

Roof snow load is defined as the weight of snow on the roof surface used in design of the building structure ibc 2012. 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. Wet snow can be nearly three times heavier than dry fluffy snow. Two feet of old snow and two feet of new snow could weigh as much as 60 lbs.

You can also find the load per square meter or square foot of roofing by opening the advanced mode. Two feet of snow on a roof with a footprint of say 28 40 feet could weigh 45 000 pounds. Per square foot of roof space so anything more than 2 feet of snow could be too much for your roof to handle. It is determined based.

Step 4 determine the flat roof snow load. Once you know these values our snow load calculator automatically finds the total weight of snow on your roof. 3 5 inches of old snow is equal to one inch of water or about 5 lbs. Wind exposure of roof.

All these variants create a challenge for determining safe snow loads. On average two feet of snow can equal up to 19 tons of weight on your roof which can significantly weaken the structure. A cubic foot of snow can weigh about 7 pounds if it s dry and fluffy. 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.

Ground snow load value. Importance occupancy and use of the building. How much snow can a roof hold. Consider removing accumulated snow from your roof to avoid collapse.

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. 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.