Roof Live Load For Residential Building

Is 875 part ii 1987 specifies the live loads for following occupancy conditions.

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. 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. 15 psf x 14ft 210 pounds per lineal foot. 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.

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. 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. Chapter 3 design loads for residential buildings.

1607 13 4 awnings and canopies. It is one of the major loads in structural design. 50 psf x 14ft 700 pounds per lineal foot. The minimum live loads per square meter area for different types of structures are given in is 875 part 2 1987.

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. 1 for garages. Notes to table 1607 1 for si. For a larger map with greater detail refer to asce 7 98.

The irc does not require any engineering design revisions for most residential structures unless the ground snow load exceeds 70 psf. Building codes such as the ibc reference asce 7 minimum design loads for buildings and other structures for the determination of design snow loads on buildings. 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. 3 20 residential structural design guide.

Live loads should be suitably calculated or assumed by the designer based on occupancy levels. In other words on a steep roof less material would be stacked in a concentrated area at one time to avoid having it slide off. The uniform design live load for occupied landscaped areas on roofs shall be determined in accordance with table 1607 1. The roof is designed for the roof live load not more than 20 psf or the snow load whichever is greater.

910 pounds per lineal foot. 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.