Psf Roof Load Shed Roof

On a roof with a slope greater than 4 to 12 the live load limit is typically adjusted downward from 20 psf to 15 psf to allow for the relatively greater dead load on the steeper roof.

Psf roof load shed roof.

Arch 331 note set 13 1 s2014abn 5 location 2uniform load psf kn m roofs ordinary flat pitched and curved roofs roofs used for roof gardens. As shown in the technical drawing below the reeds ferry standard roof has a load capacity rated at 110 pounds psf more than the highest code requirement. An inch of water depth weighs 5 2 lbs. For example appendix a indicates that one type of clay tile roof system has a live load value of 20 psf and a dead load value of 15 psf.

Per horizontal square foot is expected to support nearly 12 inches of wet heavy snow. See figure 1 headers. Af pa s appendix a lists a variety of live and dead load combinations for floors ceilings and rafters. All loads are listed as pounds per square foot of horizontal projection footprint area.

The density of snow and hence its load per square foot depends on the type of snow. For example fresh snow is soft fluffy and light. Many factors influence how a system responds to loading. It is measured in pounds per square foot psf.

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. 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. Here each square foot of roof system delivers 50 pounds of live load and 15 pounds of dead load 65 psf total to the structural support system. Factors that influence.

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. Thus a roof designed to carry a snow load of 20 lbs. 2attic loads may be included in the floor live load but a 10 psf attic load is typically used only to size ceiling joists adequately for access purposes.