But first, generally, how far can a 2×8 span without support? Depending on various factors, the maximum span for a 2×8 floor joist is 16' 6”. The maximum span for roof rafters is 23' 9”. For headers, the maximum span is 11' 2”.
Can a beam span 16 feet?
In general terms, joist or beam which spaced 16 inches apart on Centre can span 1.5 times in feet their depth in inches. A 2×10 can span upto 16 feet.
How big of a beam do I need to span 20 feet?
Wood beam size for a 20 foot span:- as per general thumb rule, for a 20 foot span, size of wood beam or lumber joist should be 2×14 which placed at 16″ apart from centre used for residential building or projects or construction in which depth of section of beam is 350mm (14″) and width of beam is 50 mm or 2″.
How far can a 2x12 span without support?
A 2x12 with an E of 800,000 psi and Fb of 790 psi also works, since it can span 15 feet and 10 inches. Given a design span of 15 feet 1 inch and a 16 inch joist spacing, first determine which size lumber will work.
How far can you span a 2x12 for a deck?
12 feet
How far can you span a triple 2x12?
Joist Spans
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Southern Pine 3-2X8
3-2X10 12'-9"
3-2X12 15'-0"
Douglas Fir-Larch, Hem-Fir, Spruce-Pine-Fir, Redwood, Cedars, Ponderosa Pine, Red Pine 3X6 OR 2-2X6
How far can a 2x10 joist span without support?
A 2×10 beam – made up of two 2x10s nailed together – can span up to 11' without support beneath a deck that is 4' wide. For a more normal-sized deck, the same beam can span 8', supporting a deck that is 8' wide.