Ready to start calculating how much lumber you ll need for your joists.
Roof deck joists span.
Span tables f7 rafters 30mm 11 f7 rafters 42mm 14 verandah beams f7 42mm sheet roof 17 verandah beams f7 42mm tile roof 20 verandah beams gl8 sheet roof 21 verandah beams gl8 tile roof 24 ridge beams f7 42mm sheet roof 25 ridge beams f7 42mm tile roof 28 internal floor joists f7 42mm 30.
Most decking is not strong enough to support longer spans than 16.
Span calculator for wood joists and rafters also available for the android os.
Before building a composite deck always read the installation instructions from the manufacturer paying.
Also available for the android os.
To learn more about deck joist sizing spacing and allowable span reference this chart.
Some builders reduce joist spacing to 12 on center to strengthen the deck frame or to increase maximum allowable joist spans.
Joist spacing for composite decking.
The 2015 irc includes a new table r507 5 deck joist spans for common lumber species.
Most decks use 16 on center spacing for joists.
As a rule the larger the deck the larger the joists.
The closer the joists are to each other the greater the distance they re able to span safely.