Porch Roof Beam Span Chart

Lumber species southern pine douglas fir douglas fir larch hemlock fir spruce pine fir redwood western cedar ponderosa pine red pine.

Porch roof beam span chart.

If you move up to 4 by 8 you re usually allowed to span up to 10 feet between posts. You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths. For more information see our disclosures here. In the example d calculates to 7 75.

Window door garage door headers supporting roof loads only. The smallest beams for patio covers are typically 4 by 6. In general the maximum span for a 4 by 6 beam is 6 feet between 4 by 4 posts. Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads.

Patio roof maximum beam rafter spans. This means the example porch would need a 6 inch by 8 inch beam. 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. Window door garage door headers supporting roof wall floor loads.

This post may contain affiliate links. A 4 by 10 can usually span up to 12 feet between posts. This tells you the size of the beam needed to support the porch s roof.