The widest span in the floor joist span table in part 2 of this tutorial module showed that floor joists can span 17 2 if they are 2 x 12s spaced 12 o c.
Floor joist wood beam span table.
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.
So the house dimensions will now be 24 x 13.
Let s expand our house beyond that 17 2 span capability to 24 feet wide.
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.
Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters.
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.
Our floor joist span tables are based on loadings given in the newer amended version of bs 6399 1.
Simplified maximum span tables for selected visual and mechanical grades of southern pine lumber in sizes 2 4 thru 2 12.
View joist rafter tables.
Also available for the android os.