Flat Roofs And Snow Load

Once you have the ground snow load p g you can compute the flat roof snow load p f.

Flat roofs and snow load.

The density of snow and hence its load per square foot depends on the type of snow. Neither of these are accurate. If your roof is flat it is more likely to have snow load problems than if it is pitched. In colder regions the design snow load represents snow deposited by multiple snow events.

On the other hand snow that stayed on your roof for a few days will settle and while it seems that the cover gets thinner its weight doesn t change it s just the density that is different. This may also be true in some more moderate climates as well. There are a few common misconceptions regarding flat roofs that are stubbornly persistent. 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.

Other considerations for sloped roofs can be found throughout chapter 7 of asce 7 10. Another is that they cannot handle as much snow weight as pitched roofs because the snow sits directly on the roof. 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. One of them is that flat roofs leak more easily than pitched ones.

First figure out how deep the snow is piled up there. In our case let s assume that our structure has a flat roof roof slope 5. Why snow load information. Employing a combination of steel and wood on this connector roof the architects engineered the roof to support sustained snow loads while capably protecting the walkway below from snow accumulation.

A great deal of confusion currently exists among engineers architects recreation specialists and maintenance personnel concerning the proper snow loading to use for the design and maintenance of trail bridges building roofs and other structures in mountainous high snow load areas. Flat roof snow loads p f the snow load that is applied to our structure is not the ground snow load but in most cases the flat roof snow load. For example fresh snow is soft fluffy and light.