This sample table gives minimum floor joist sizes for joists spaced at 16 inches and 24 inches on center o c for 2 grade lumber with 10 pounds per square foot of dead load and 40 pounds of live load which is typical of normal residential construction.
Max span for 2x12 floor joist.
We ve included 2x6 2x8 2x10 and 2x12 joist spans and more.
View joist rafter tables.
2 grade of douglas fir are indicated below.
A 2x8 up to 12 feet.
Joists that are closer together can support more weight which allows the joists to span a longer distance than joists spaced further apart.
True floor joist span calculations can only be made by a structural engineer or contractor.
Span calculator for wood joists and rafters also available for the android os.
Dead load weight of structure and fixed loads 10 lbs ft 2.
1 ft 0 3048 m.
Live load is weight of furniture wind snow and more.
In typical deck construction with a ledger on one side of the joist and beam on the other the size of the joists is driven by the size of the deck and based on the general maximum spans mentioned above.
Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters.
2x10 to 15 feet and 2x12 to 18 feet.
1 psf lb f ft 2 47 88 n m 2.
Simplified maximum span tables for selected visual and mechanical grades of southern pine lumber in sizes 2 4 thru 2 12.
Maximum floor joist span for no.
See our complete chart of floor joist size span and spacing requirements before you build.
The maximum span distance for 12 inch spacing is greater by as much as 30 percent compared to 24 inch spacing.
Also available for the android os.
For example in the joist span table below the highlighted cell shows that 2 x 8 southern yellow pine joists that have a grade of 2 and are spaced 24 apart can have a maximum span of 10 feet 3 inches 10 3 if designing for a live load of 40 lbs ft 2.