Table of Contents
What is the maximum span for deck beams?
Joists spaced the standard 16 inches apart can span 1.5 times their depth in feet. A 2×6 joist can span up to 9 feet, a 2×8 can span up to 12 feet, and a 2×10 can span up to 15 feet.
What size should deck beams be?
For an 8′ joist span, either 2x8s at 24” O.C. or 2x6s at 16” O.C. are acceptable. For sizing the beam, use a joist length of 10′ (8’+2′) and a posting spacing of 10′. The Beam Size table indicates that the beam may be either two 2x10s or two 2x12s, depending on wood used.

How far can a deck beam span without support?
A 2×6 spaced 16 inches apart can span a maximum distance of 13 feet 5 inches when used as a rafter, 10 feet 9 inches when used as a joist, and 6 feet 11 inches when used as a deck beam to support joists with a 6-foot span.
What is deck span?
A deck joist span is a distance between two load-bearing points. Deck joist spacing usually is 16 inches on center but can vary between 12 and 24 Inches.
How far can a triple 2×10 deck beam span?

For a more normal-sized deck, the same beam can span 8′, supporting a deck that is 8′ wide. You can also triple a 2×10 beam. In that case, you could span up to 15′ for decks that are 4′ wide and up to 10′ for decks that are 8′ wide.
What is a deck beam?
In deck construction, a girder (or a beam) is a board or a composite of more than one board that serves as a supporting structure for the deck joists, which meet it perpendicularly.
What is a beam span?
Span is the distance between two intermediate supports for a structure, e.g. a beam or a bridge. A span can be closed by a solid beam or by a rope. The first kind is used for bridges, the second one for power lines, overhead telecommunication lines, some type of antennas or for aerial tramways.
Do deck beams need to be doubled?
The problem now is that too many posts will be required, so the best thing to do is to double up or triple the deck beams to double the strength and allow for wider spacing of posts and beams. Now, two pieces of 2×6 fastened together will be comfortable enough to serve and support 6 feet of the joists and the decking.
Can I use 2×6 for deck beams?
You can use 2×6 as deck joists if the deck is low enough to the ground as not to require guard railing. When using S-P-F 2×6 deck joists, the span must not be greater than 9’0″ (2.73m) with joists at 16″ o.c. (400mm), and 9’10” (3.01m)with spacing at 12″ (300mm).
How far can a 2×10 deck beam 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. You can also triple a 2×10 beam.
How far can a 3 2×10 beam span without support?
Joists
Joist Size | Spacing | Douglas Fir or Larch |
---|---|---|
2×8 | 24” OC | 10′-3” |
2×10 | 12” OC | 17′-9” |
16” OC | 15′-5” | |
24” OC | 12′-7” |
What are deck beams called?
girders
Beams, also called girders, are deck components that support the frame of the deck. Beams are installed alongside the rim joists (joists at the perimeter) or below the joists to support the frame of the deck. For larger decks, more beams may be installed intermittently for extra support.
What is deck beam?
noun A strong transverse beam of timber or iron stretching across a ship from side to side, in order to support the deck and retain the sides at their proper distance.
How far can a 2×8 deck beam span?
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”. Finally, a single deck beam has a maximum span of 5′ 11” and double maxes out at 8′ 9”.
How big of a beam do I need for a 16 foot span?
For a 16 foot span, you will need atleast 3-2×14 or 6×14 size of wood beam. Thus, a 3 nailed 2×14 or 3-2×14 or 6×14 wood beam can allow to span 16 feet. For a 16-foot spans, the wood beam has to be at least 14 inches in depth and 6″ in width (3-2×14) used for residential building, wood frame structure or projects.