According to the 2012 irc codes any beam joist or header shall never have a bearing of less than 1 1 2.
Wood roof beam span table.
Here we have a wood framed gable roof.
Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads.
The figures are based on quality materials.
View joist rafter tables.
Our floor joist span tables are based on loadings given in the newer amended version of bs 6399 1.
Limited to span in inches divided by 360.
Span tables for jois ts and rafters american wood council 4 span tables for joists and rafters american wood council design criteria.
The image below shows a cross section of our simple 12 x 13 house from the joist span tables section of this tutorial.
For lesser grades spans should be shorter.
The tables below give maximum spans for rafters and beams.
Span tables for domestic floor joists to bs 5268 7 1 note.
Tables 13 14.
Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters.
Floor beam span tables of residential structural design we will now look at roof rafter and beam design.
Let s consider a basic gable wood roof framing design.
You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths.
Span calculator for wood joists and rafters also available for the android os.
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.
Simplified maximum span tables for selected visual and mechanical grades of southern pine lumber in sizes 2 4 thru 2 12.
Deflection for 30 psf live load.
Strength live load of 30 psf plus dead load of 10 psf determines the required bending design value.
Continuing on from part 3.
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.
Also available for the android os.
This means that some values are slightly more conservative than span tables from other sources if those do not include the amended guidance.
On longer spans the beam may require much more bearing space as indicated by this table.
Beams of more than one ply must be fastened together with either nails or bolts.
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.
