The roof is designed for the roof live load not more than 20 psf or the snow load whichever is greater.
Roof live load for residential building.
1 inch 25 4 mm 1 square inch 645 16 mm 2 1 pound per square foot 0 0479 kn m 2 1 pound 0 004448 kn 1 pound per cubic foot 16 kg m 3.
The uniform design live load for occupied landscaped areas on roofs shall be determined in accordance with table 1607 1.
3 20 residential structural design guide.
The minimum live loads per square meter area for different types of structures are given in is 875 part 2 1987.
The uniform design live load in unoccupied landscaped areas on roofs shall be 20 psf 0 958 kn m 2.
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.
Is 875 part ii 1987 specifies the live loads for following occupancy conditions.
Chapter 3 design loads for residential buildings.
The irc does not require any engineering design revisions for most residential structures unless the ground snow load exceeds 70 psf.
1 for garages.
Used but they typically defined the load cases or combination stress or strength limits and deflection limits.
15 psf x 14ft 210 pounds per lineal foot.
Notes to table 1607 1 for si.
50 psf x 14ft 700 pounds per lineal 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 a larger map with greater detail refer to asce 7 98.
Live loads should be suitably calculated or assumed by the designer based on occupancy levels.
It is one of the major loads in structural design.
The roof snow load is defined as the weight of.
910 pounds per lineal foot.
Load types loads used in design load equations are given letters by type.
D dead load l live load l r live roof load w wind load s snow load e earthquake load r rainwater load or ice water load.
Floors in garages or portions of buildings used for the storage of motor vehicles shall be designed for the uniformly distributed live loads of table 1607 1 or the following concentrated loads.
In my region on cape cod we have a ground snow load design of 25 psf which is a greater design load than the live load 12 psf to 20 psf over an entire roof system.
To correctly apply the values of the tables and the prescriptive methods of construction build ers must know the structural design criteria in the planning chapter of the code.
It is important to list live load dead load and total load separately because live load is used to compute stiffness and total load is used to calculate strength.
