True floor joist span calculations can only be made by a structural engineer or contractor.
Maximum span for 2x10 floor joist.
Joists that are closer together can support more weight which allows the joists to span a longer distance than joists spaced further apart.
Dead load weight of structure and fixed loads 10 lbs ft 2.
A 2 2x10 can span 10 feet and so on.
The numbers in gray indicate the distance between the support posts.
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.
Span calculator for wood joists and rafters also available for the android os.
These tables can also be used to determine deck joist span.
The maximum span distance for 12 inch spacing is greater by as much as 30 percent compared to 24 inch spacing.
When supporting joists that span 12 feet with no overhang beyond the beam a double ply beam can span in feet a value equal to its depth in inches.
Hem fir 2 joists with a live dead load of 40 10 psf.
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.
Floor joist table joist size joist spacing maximum span.
2 2x10 o i 6 2 2x4 2 2x4 2 2x6 2 2x6 2 2x6 2 2x8 2 2x8 2 2x10 2 2x10 s.
Spans in this table were derived from the irc table r502 3 1 2 design criteria.
The illustrations one for cantilever joists and one for flush rim beam hung joists point out where joist span measurements are taken from the saddle of the ledger mounted joist hanger to the center of a dropped beam or saddle of the.
Our joist span charts are for wood joists with a maximum dead load of 10 pounds per square foot and a live load of 40 pounds per square foot.
2 grade of douglas fir are indicated below.
Live load is weight of furniture wind snow and more.
Span entries are listed for 2 6 through 2 12 joists and 12 in 16 in and 24 in.
Dimensional lumber deck beam span chart.
2x10 to 15 feet and 2x12 to 18 feet.
The larger the deck the larger the joists.
This chart is for basic reference only.
If you have any questions.
1 ft 0 3048 m.
A 2x8 up to 12 feet.
Live load represents the weight of furniture snow etc.
1 psf lb f ft 2 47 88 n m 2.
A double 2x12 beam can span 12 feet.
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.