6x6 Beam Span Chart
Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads.
6x6 beam span chart. Obviously the larger the beam the greater the distance it can span between posts. The numbers in gray indicate the distance between the support posts. Refer to the deck beam span table below to assist in determining the maximum span of a given beam between posts.
Beam span calculator for help simply click on the beside the section you need help with watch this tutorial video. Lumber species southern pine douglas fir douglas fir larch hemlock fir spruce pine fir redwood western cedar ponderosa pine red pine. Beam may be solely responsible for carrying a specific design load.
Numbers in blue are joist spans beam to beam or house to beam. You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths. A double 2x12 beam can span 12 feet.
Douglas fir is one of the most widely used and strongest wood species commonly used for six by six lumber sometimes marketed as hem fir or fir larch because of its close association with hemlock and larch spruce runs a close second with respect to wood strength. A redwood 4x6 beam should span no more than 6 between supporting posts. A 2 2x10 can span 10 feet and so on.