Roof Design For Heavy Snow Load

Shake or slate roofs there is no stronger protection against heavy snow loads than shake or slate roofs.

Roof design for heavy snow load.

Proper roof ventilation and high r value roof insulation is essential to minimizing ice dam formation. Depending on your region you may need to design for a maximum snow load of anything between zero to 65 pounds per square foot or roughly 0 3 kpa. Metal roofing also protects the structure of a home from the great weight of accumulation of ice that create ice dams. The truss could be designed based on the assumption that ground snow is being used as the roof design snow load pg 25 psf.

These roofs are typically found on industrial buildings. In fact actual breakage of rafters is fairly. Consider the prevailing winds and building orientation a lot of people think snow loads are constant across a building s roof. Framing table for maximum roof rafter spans.

It is an old fashioned design but it is very suitable for most of the houses and works very well in sweeping of great piles of the snow automatically because of its shape and when the roofs are not stuck up with snow the inner portion stays warm and cozy for the people to live in and fight against the climate and survive. If you aren t sure if your home is in danger of heavy snow loads here are a few signs to pay attention to. Is a roof that has been unequally loaded due to blowing and drifting snow more prone to failure. However some residential homes also have this design.

A christopher deblois a structural engineer with palmer engineering in tucker ga responds. The wooden origins and the slants are applied to the design so that the snow does not pile up in the roof and make it too much heavier for the walls to withstand their load. Shed dormers are easier to waterproof and shed snow better than gable dormers. However when wind blows as it often does during snowfalls the weight of the snow becomes unevenly distributed.

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. If the design necessitates a roof slope that drains onto a traffic area snow retention devices should be provided to hold the snow in place. Or the truss could be designed based on the assumption that the 25 psf roof snow load is a factored ground snow load in which case a ground snow load is back calculated using asce 7 based on the specified roof snow load pg 25 psf. Let s look at the sample table below which shows maximum rafter spans for a snow load of 31 3 pounds per square foot psf.

To offset the weight variance a designer and engineer should design the building accordingly. Metal roofing is tough and durable protection for your home that can withstand heavy loads of snow and even hail.