Porch Roof Beam Span Chart

F stands for the beam s fiber strength in bending which depends on the species of wood.

Porch roof beam span chart.

Window door garage door headers supporting roof wall floor loads. For more information see our disclosures here. In the example the beam spans the 10 foot width of the roof. For the initial calculation f can be estimated at 1 000.

You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths. Window door garage door headers supporting roof loads only. 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. Patio roof maximum beam rafter spans.

L stands for the span of the beam in feet. This post may contain affiliate links. Fill in the parts of the formula that are already known. Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads.

In general the maximum span for a 4 by 6 beam is 6 feet between 4 by 4 posts. A 4 by 10 can usually span up to 12 feet between posts. If you move up to 4 by 8 you re usually allowed to span up to 10 feet between posts. The total load is 4 000 pounds.