The larger the deck the larger the joists.
Floor joists for deck.
Deck joists have a different maximum span length depending upon the size spacing and framing material that you re creating your deck with.
Composite deck joist space.
Deck joist spacing should never exceed 16 on center with the exception of max deck boards which allow for maximum 24 on center.
Here s a helpful chart covering the most popular wood framing species and their maximum allowed spans.
For a more rigid feel 12 or less may be preferred.
I prefer to double the outside joists as do some deck builders which adds 2 joists for a total of 11.
The subfloor is the decking installed on top of flooring joists.
That means these joists can span the 12 foot depth of the deck and the beam can be located at the perimeter.
The finished floor is then installed on top of the subfloor.
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.
The thickness of plywood panels in a subfloor is regulated by the.
Nine joists will be needed for the 16 foot width.