Design properties 16 floor span and load tables 17 allowable holes 18 roof span and load tables 19 cantilevers 20 21.
Floor joist size 13 span.
For example if you double the thickness or number of joists in a floor the distance the boards can span will increase by approximately 25.
2 grade of douglas fir are indicated below.
The larger the deck the larger the joists.
1 psf lb f ft 2 47 88 n m 2.
For best results refer to our wood and composite deck joist span table.
Joist span table use these tables to determine floor joist spans based on grade of lumber size of joist floor joist spacing and a live load of 30 lbs ft 2 or 40 lbs ft 2 these tables can also be used to determine deck joist span.
The width of a board is an important factor in determining the distance a floor joist can span playing a much larger role than the thickness.
When building a house or even a deck it is important to confirm you have the correct joist sizes spans and spacing before you get started.
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.
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.
2 5 x 9 5 x 16 2 1 2 solid sawn lumber nailing flange provides quicker sheathing installation.
Floor joist table joist size joist spacing maximum span 2 x 6 12 on center 10 0 16 9 1 19 2 8 7 24 7 11 2 x 8 12 on center 13 2.
True floor joist span calculations can only be made by a structural engineer or contractor.
See the image below for an example of joists spaced 16 on center 16 o c.
Joists design properties 6 floor span and load tables 7 8 tips for preventing floor noise 8 allowable holes 9 cantilevers 10 11 roof span and load tables 12 13 framing connectors 14 15 section 2.
Dead load weight of structure and fixed loads 10 lbs ft 2.
Joist span and spacing is set by your local building code.
Openings can be strategically cut per manufacturer s recommendations in the i joist web to allow for wiring duct work and plumbing.
Live load is weight of furniture wind snow and more.
While most residential construction uses 2x8 joists with 16 inch spacing there are many other factors you need to consider when determining the proper joist span length.
Floor joist span tables for various sizes and species of wood.
Maximum floor joist span for no.
I joists are more uniform in strength stiffer and straighter than regular framing lumber.
