They hold the snow in place and keep it from accumulating and then sliding off in large slabs that can be dangerous.
Overweight of snow roofing.
If your roof is 1 000 square feet the total snow load is 15 000 pounds of snow.
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.
To figure out the load on your roof take the depth of snow in feet and multiply it by the weight of a cubic foot of snow.
Snow loads are influenced by elevation general weather and moisture patterns slope direction exposure roof or trail bridge configuration and wind direction and severity.
3 5 inches of old snow is equal to one inch of water or about 5 lbs.
Per square foot of roof space which is beyond the typical snow load capacity of most roofs.
On average two feet of snow can equal up to 19 tons of weight on your roof which can significantly weaken the structure.
Overestimation of snow loads can unnecessarily increase the cost of construction.
Consider removing accumulated snow from your roof to avoid collapse.
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 roof slopes between 4 12 and 6 12 rough textured roofing materials work best.
If the snow weighs 10 pounds per cubic foot and there are 1 5 feet on the roof each square foot of the roof is getting 15 pounds of pressure.
However many forecasters are predicting that the upcoming winter season will be unusually harsh in many parts of the u s so it s helpful to know how to identify snow damage to a roof and what to do about it.
When the snow melts it creates layers of ice so this overweight of snow and ice can have serious repercussions on the condition of your roof.
People have been killed by snow avalanches sliding off roofs during big snow winters.
Your equation for determining snow load s x 1 25 p is fairly straightforward math.
On average relatively dry snow weighs around 5 pounds a foot while wet snow can tip the scales at more than 20 pounds per foot to calculate the snow load on your roof assume that every inch deep of snow equals 1 25 pounds.
An overweight puts the structure of your roof in jeopardy and this can cause in the worst cases a complete collapse of the roof.
Being attentive to the warning signs and take measures to prevent an accumulation of snow or ice are the best means to avoid the consequences of a roof collapse.