# Floor joist size in residential construction

## What size should floor joists be?

In general terms, joists spaced 16 inches on center can span 1.5 times in feet their depth in inches. A 2×8 up to 12 feet; 2×10 to 15 feet and 2×12 to 18 feet. The larger the deck, the larger the joists.

## How much weight can 2×8 floor joists hold?

Just so, how much weight can 2×6 floor joists hold ? To give you a general idea though, floor joists are sized to support 40 pounds per square foot of “live” load (moving weight ) or 10 psf “dead” (stationary) load . How much weight can a 2×6 joist hold ?

Joist Spacing (o.c.) 12″
Species Size Allowable Span
Southern Pine 2×6 9′-11″
2×8 13′-1″
2×10 16′-2″

## How do you measure for floor joists?

Is there a simple way to size floor joists ? A. Carl Hagstrom responds: The rule of thumb that I like to use when sizing uniformly loaded residential floor joists is “half the span plus two.” First, round the clear span of the floor joist up to the nearest foot, and divide by two. Then add two to the answer.

## Are two 2×6 stronger than a 2×8?

Similarly, are two 2×6 stronger than a 2×8 ? In bending, a joist composed of two 2×6’s (true dimension 1.5 inches x 5.5 inches) are slightly stronger than a single 2×8 true dimensions 1.5 inches by 7.25 inches.

## How far can a 2×6 floor joist span without support?

One may also ask, how far can a floor joist span without support? Joist Spans A live load of 60 pounds per square foot demands more support and shorter spans. Spaced at 12 inches, the joist may only span 16 feet 8 inches. At 16 inch spacing, 15 feet 2 inches and 13 feet 3 inches at 24 inch spacing.

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## How much weight can 2×6 floor joists hold?

50 pounds per square foot

## How far can you span a 2×6 floor joist?

Max. Live Load 30 lbs/ft2 (1436 N/m2)

Maximum Span (ft – in)
Nominal Size ( inches ) Joist Spacing Center to Center ( inches ) Lumber Grade
2 x 6 16 10′ – 11″
24 9′ – 7″
2 x 8 12 15′ – 10″

## Can a House floor collapse?

A floor collapse typically occurs because a property owner did not recognize the progressing signs of a loss of structural integrity in their building. For example, if there is evidence that a structure has rotten wood beams, this can be an issue that can lead to a floor collapse .

## Are floor trusses stronger than joists?

Pros: Span longer distances than traditional joists , removing the need for walls in some areas. Lighter weight. Stronger than traditional joists .

## How much weight can a 2×6 support horizontally?

So the area between two 2×6 , 6′ long, on 2′ intervals would have to be able to support 2x6x40=480 pounds of weight . Actually, slightly more since the formula is for 8′-6″ spans but it just gives you a little bit of extra load for just in case.

## What is the load bearing capacity of a wood 2×6?

Engineer 10 adds that a No. 2 2×6 over a 16-ft. span can carry 10 psf while a 2×8 will carry 20 psf. Sistering the two together means a load – carrying capacity of 30 psf.

## How far can a triple 2×6 beam span?

A triple 2×6 beam over a span of 10′ feet should be more than sufficient for normal deck loads. Maximum span for a single 2×6 #2btr yellow pine is around 9′ feet . So YES you should be fine with triple 2×6..