1603 1 3 roof snow load.
Roof live load porch roof.
There are also factors such as deflection elasticity and wood species that come in to play.
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.
So with the roof dance floor example per ibc the live load would not be roof live load but live load assuming the live load magnitude exceeded 20 psf.
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.
Chapter 3 design loads for residential buildings.
For a larger map with greater detail refer to asce 7 98.
Ibc 2012 defines live load l as roof live load greater than 20 psf and floor live load.
3 20 residential structural design guide.
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.
Roof live load l r is defined as roof live load of 20 psf or less.
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.
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.
The ground snow load p gf and the flat roof snow load p and if applicable the sloped roof snow load p s shall.
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.
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.
Also whether live load reduction has been applied.
Determine the load per square foot that the roof must support.
The dead load is constant and is estimated as 10 pounds per square foot for wood framed construction.
Many small porch and patio roofs or canopies on residential buildings particularly those located nowhere near public streets.
1603 1 2 roof live load.
