Roof Load Beam Span

Window door garage door headers supporting roof loads only.

Roof load beam span. 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. You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths. F stands for the beam s fiber strength in bending which depends on the species of wood. L stands for the span of the beam in feet.

Standard 2 by 12 beams on 16 inch centers are used to span 15 feet. An essential part of planning a patio roof or gazebo project is determining the number size and spacing of rafters beams and posts according to the loads they will carry. 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. For the initial calculation f can be estimated at 1 000.

50 psf x 14ft 700 pounds per lineal foot. 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. 910 pounds per lineal foot. 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.

Window door garage door headers supporting roof wall floor loads. Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads. 15 psf x 14ft 210 pounds per lineal foot.