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. With this in mind, the depth of the joist determines the spacing of the beams. What is this?

## How far can a 2X10 deck beam span?

Dimensional Lumber Deck Beam Span Chart

Joist Spans
Douglas Fir-Larch, Hem-Fir, Spruce-Pine-Fir, Redwood, Cedars, Ponderosa Pine, Red Pine 3X8 OR 2-2X8 6′-7″
3X10 OR 2-2X10 8′-1″
3X12 OR 2-2X12 9′-5″
4X6 6′-2″

## How far can a deck beam span without support?

For a deck with a maximum live load of 40 pounds per square foot and a dead load of 10 pounds per square foot (for a total load of 50 pounds per square foot), the maximum span is 9 feet 5 inches for a No. 1 quality 2×6 joist spaced 16 inches apart.

## How do I know what size beam I need for my deck?

Use joist length “b” to determine the size of Beam 2. Joist size is determined by using the longest span joist (7′). The Joist Span indicates that 2x6s at 24” O.C. would be adequate for this span. For Beam 1, use a joist length of 13′, (6’+7′) and a post spacing of 9′.

## How far can a double 2X8 deck beam span?

For example, a double 2×8 beam can span 8-ft. -0 in. when the deck joists are 6 ft. long.

## What is the maximum span for deck joists?

Most decks use 16″ on center spacing for joists. Most decking is not strong enough to support longer spans than 16″. Some builders reduce joist spacing to 12″ on center to strengthen the deck frame or to increase maximum allowable joist spans.

## 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″.

## What size beam do I need to span 15 feet?

Thus, for a 15 foot span, you will need atleast 3-2×12 or 6×12 size of wood beam. For a 15-foot spans, the wood beam has to be at least 12 inches in depth and 6″ in width (3-2×12) used for residential building, wood frame structure or projects.

## Can I use 2×8 for deck beams?

Deck beams sit on top of the posts and support the deck joists. If the outside edge of your deck is at least 17” above grade, a double 2×8 deck beam should be installed to support the joists along the outside. The joists will then extend over the beam in a cantilever position.

## How far can a double 2×8 beam span without support?

Using this rule, a 2×6 will span 9 feet, a 2×8 will span 12 feet, and a 2×10 will span 15 feet. As you can see, the larger the depth, the longer the span.

## What is the maximum span for a 2×8 deck joist?

A rule of thumb is 1.5 times a joist’s depth but in feet when spaced at 16” centers. In general, a 2×8 will span 1.5 x 8, so 12-feet.

## Can I use 2×8 for deck joists?

2×8 for joists will be fine, with 16″ OC. Should use 2×10 for beams but 2×8 will be fine as well. If you are worried you can triple the 2×8 for the beams but double will be sufficient. You should put the beams at 7 and 14 feet out from the house, with the piers you should do 3 per beam with spacing of 1, 7, 13.

## How far can a triple 2×8 beam span?

How far can a triple 2×8 beam span:- as per general rules and guidelines, #2 grade southern pine of a triple 2×8 deck beam can span upto 10 to 11 feet when total load of 50 psf (40 psf live load + 10 psf dead load) with deflection limit L/360.

## What size beam do I need to span 16 feet?

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.

## How far can a 8X8 beam span?

20 to 25 feet is a serious span – an 8X8 won’t even come close. From contributor P: Figure an inch per foot of span. 20′ would require 20″, 25′ would require 25″.

## What size beam do I need for an 18 foot span?

Wood beam size for a 18 foot span:– as per general thumb rule, for a 18 foot span, size of wood beam or lumber joist should be 2×12 which placed at 16″ apart from centre used for residential building or projects or construction in which depth of section of beam is 300mm (12″) and width of beam is 50 mm or 2″.

## How far can a triple 2×10 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.