Roof Load Beam Span

L stands for the span of the beam in feet.

Roof load beam span.

Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads. 910 pounds per lineal foot. 50 psf x 14ft 700 pounds per lineal foot. You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths.

The theoretical size of a load bearing beam required to support a particular weight is easy to calculate but the choice of the actual beam depends on taking into account the factors of the particular situation. Window door garage door headers supporting roof loads only. The total load is 4 000 pounds. 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.

Tables providing size selections for various beam spans and loading combinations for southern pine dimension lumber and southern pine glued laminated timber are available for the following applications. For the initial calculation f can be estimated at 1 000. Maximum rafter spans for a patio roof in areas with mild climates patio roofs are generally designed for loads of 30 psf pounds per square foot. Fill in the parts of the formula that are already known.

In the example the beam spans the 10 foot width of the roof. Standard 2 by 12 beams on 16 inch centers are used to span 15 feet. F stands for the beam s fiber strength in bending which depends on the species of wood.