Porch Roof Beam Span Chart

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.

Porch roof beam span chart.

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. Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads. The total load is 4 000 pounds. This post may contain affiliate links.

Fill in the parts of the formula that are already known. For the initial calculation f can be estimated at 1 000. F stands for the beam s fiber strength in bending which depends on the species of wood. A 4 by 10 can usually span up to 12 feet between posts.

For more information see our disclosures here. Window door garage door headers supporting roof wall floor loads. Build your patio cover or deck designing with roof rafter span tables board can span 16 ft for a wall pergola patio roof maximum beam rafter spanspatio roof beam calculatorpatio coversplease plete. In general the maximum span for a 4 by 6 beam is 6 feet between 4 by 4 posts.

If you move up to 4 by 8 you re usually allowed to span up to 10 feet between posts. Window door garage door headers supporting roof loads only. You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths. In the example the beam spans the 10 foot width of the roof.