Flat Roofs And Snow Load

Other considerations for sloped roofs can be found throughout chapter 7 of asce 7 10.

Flat roofs and snow load.

The snow load that is applied to our structure is not the ground snow load but in most cases the flat roof snow load. Wind seismic building weight furniture occupants etc. For example 18 inches would be 1 5 feet. Another is that they cannot handle as much snow weight as pitched roofs because the snow sits directly on the roof.

You need to use a snow load formula for flat roofs. As a result equation 7 1 which accounts for loss between events will result in a non conservative value. The easiest way is to push a yardstick into the snow on the roof selecting an area that looks typical of the overall snow depth. 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.

Flat roofs can t possibly support all the extra weight a totally valid concern but rest assured your architect and engineer have this in mind when designing the roof structure. Asce 7 05 equation 7 1 assumes that the snow load results from multiple events. In our case let s assume that our structure has a flat roof roof slope 5. Snow is actually one of the easiest to design for and all.

There are a few common misconceptions regarding flat roofs that are stubbornly persistent. The flat roof snow load is calculated using formula 7 3 1. Express the result in feet rather than inches. Minimum flat roof snow load values.

First figure out how deep the snow is piled up there.