Roof Live Load Porch Roof

Roof live load l r is defined as roof live load of 20 psf or less.

Roof live load porch roof.

Applied shall be indicated. Chapter 3 design loads for residential buildings. Consult local building codes for snow load capacity and reference the span tables for joists and rafters published by the american wood council awc as a general rule roofs that have a high human occupancy rate should be framed with rafters every 16. In areas where the ground snow load is less than 15 psf the minimum roof live load refer to section 3 4 is usually the controlling rgavity load in roof design.

Many small porch and patio roofs or canopies on residential buildings particularly those located nowhere near public streets. Determine the load per square foot that the roof must support. 1603 1 3 roof snow load. Also whether live load reduction has been applied.

Location 2uniform load psf kn m roofs ordinary flat pitched and curved roofs roofs used for roof gardens roofs used for assembly occupancies roofs used for other occupancies awnings and canopies fabric construction supported by a skeleton structure screen enclosure support frame. For a larger map with greater detail refer to asce 7 98. Using the term live loads when referring to roofs might make you scratch your head initially because roofs unlike floors aren t asked to bear the weight of things such as furniture and occupants of a home what you would normally think of as a live load. There are also factors such as deflection elasticity and wood species that come in to play.

Ibc 2012 defines live load l as roof live load greater than 20 psf and floor live load. The live load depends on the maximum snow load in your area. 3 20 residential structural design guide. 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.

The ground snow load p gf and the flat roof snow load p and if applicable the sloped roof snow load p s shall. 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. The roof load is composed of a dead load and a live load. The roof live load used in the design shall be indicated 780 cmr 1607 11.

Prior to the 2012 ibc these roofs were designed for standard roof live loads or local ground snow loads typically in the range of 20 or 30 pounds per square foot.