How To Decide Roof Dead Load

Joist span bridging girder load width half joist span live load on roof local requirements for wind and snow.

How to decide roof dead load.

Here weight means the downward force the structure exerts on the earth. Dead load is the weight of all the permanent parts of a structure. 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. 15 psf x 14ft 210 pounds per lineal foot.

For dead loads you are correct. However in my practice i typically use the horizontal run of the roof for both types of load. There are several convenient ways to express the intensity of dead loads. The dead load on a roof is the weight of the roof structure itself along with any permanently attached materials or structures on the roof so it must be designed first of all to support itself.

3 3 dead loads dead loads consist of the permanent construction material loads comprising the roof floor wall and foundation systems including claddings finishes and fixed equipment. When volume v is multiplied by density a force value results. Dead load is the term structural and mechanical engineers use to describe the weight of all the permanent parts of any structure. 910 pounds per lineal foot.

Overturning should also consider roof uplift forces unless a separate load path is designed to transfer those forces. Technically you should use the actual rafter length when adding up the weight of roofing materials. Ft dead load of roof of wood shingle construction 10 lbs. Live load on attic floor local requirements.

The common symbol for density is. Floors roofs and walls most floor roof and wall systems have fairly uniform density and their weights can be expressed in terms of weight per unit area.