Psf Roof Load Shed

Factors that influence.

Psf roof load shed.

All loads are listed as pounds per square foot of horizontal projection footprint area. A typical wood frame floor covered with carpet or vinyl flooring has a dead load of about 8 pounds per square foot. 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. 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.

For roof live loads of 12 psf or 16 psf. The dead load on a floor is determined by the materials used in the floor s construction. See figure 1 headers. The loads are based on adjusted roof snow loads from the governing building code.

The density of snow and hence its load per square foot depends on the type of snow. 0 9d 1 0w a load factor of 1 6 when adding to load 7. 1 2d 1 0e l 0 2s when h loads are present they shall have 6. Buildings wider than 8 have a double 2 6 center beam to ensure minimal deflection.

Minimum design loads for buildings and other structures location uniform load psf. 0 9d 1 0e effect or 0 9 when resisting the load when permanent. Af pa s appendix a lists a variety of live and dead load combinations for floors ceilings and rafters. The design roof snow load for residential buildings in mn is set by state statutes and is 42 pounds per square foot psf in northern mn and 35 psf in southern mn.

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. However many agricultural buildings are built using a 20 psf snow load which would be expected to handle six feet of dry fluffy snow or one foot of wet heavy snow. If there s wall board covered ceiling suspended from the underside of that floor the dead load increases to about 10 pounds per square foot. Minimum uniformly distributed live loads adapted from sei asce 7 10.

Standard floors use 3 4 exterior grade plywood with double layer and pressure treated plywood optional. See this floor construction video for details. For roof live loads less than 20 pounds per square foot psf rafter spans and required e values tabulated for 20 psf shall be permitted to be adjusted in accordance with the fol lowing table. Many factors influence how a system responds to loading.