Deck joists
How far can a deck joist span?
11′-10″max joist span
Allowable overhang beyond the beam: 2′-0″ (never more than one quarter of the actual back-span).
Deck calculator
Deck joist & beam spans
Size deck joists and beams straight from the American Wood Council's DCA6 prescriptive deck guide — the residential deck tables most building departments accept.
Deck beams
What beam carries the joists?
Pick the total joist span the beam carries (joists framing one side) and a built-up or solid beam size to read its maximum beam span.
7′-9″max beam span
Source: DCA6 — Prescriptive Residential Wood Deck Construction Guide, 2015 (based on 2015 IRC) — Table 2 (deck joists) and Table 3A (deck beams) (American Wood Council).