Wood Roof Beam Span Table

Let s consider a basic gable wood roof framing design.

Wood roof beam span table. Raised wood floor foundations. Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters. Table 9 1 in span tables for joists and rafters figure 5 gives a required compression value of 237 psi for a span of 16 feet and bearing length of 1 5 inches. Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads.

For lesser grades spans should be shorter. Span tables for jois ts and rafters american wood council 4 span tables for joists and rafters american wood council design criteria. On longer spans the beam may require much more bearing space as indicated by this table. This means that some values are slightly more conservative than span tables from other sources if those do not include the amended guidance.

Continuing on from part 3. Our floor joist span tables are based on loadings given in the newer amended version of bs 6399 1. Floor beam span tables of residential structural design we will now look at roof rafter and beam design. Span calculator for wood joists and rafters also available for the android os.

Anything 5 and above we always at least double cripple. You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths. Also available for the android os. The figures are based on quality materials.

View joist rafter tables. Tables 13 14. The tables below give maximum spans for rafters and beams. The tables permit a bearing length of up to 3 5 inches but since 1 5 is probably the worst case that you ll encounter for joist or rafter bearing it s a safe value.

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. Limited to span in inches divided by 360. Beams of more than one ply must be fastened together with either nails or bolts. Deflection for 30 psf live load.

According to the 2012 irc codes any beam joist or header shall never have a bearing of less than 1 1 2. Simplified maximum span tables for selected visual and mechanical grades of southern pine lumber in sizes 2 4 thru 2 12. The image below shows a cross section of our simple 12 x 13 house from the joist span tables section of this tutorial. Span tables for domestic floor joists to bs 5268 7 1 note.