For example, the highlighted cell (below) shows that a 2″ x 6″ Southern Yellow Pine joist, with a grade of #2, and spaced 24″ apart can have a maximum span of 10 feet – 0 inches (10-0), if you are designing your structure to support a plaster ceiling.
Decking made of 2x4s or 2x6s can span up to 24 inches. If you will run decking at an angle, you might need to put the joists closer together.
Can I use 2×6 for deck joists? If the span is only 8 ot 9′ then yes, they will work. You would be better to check the national building code – joist spacing – before you buy your lumber. LLive loading on a deck is estimated at 40 pounds per square foot (10 psf for static load) usually.
How far can a 2×6 Rafter span without support? The table states that 2 X 6 rafters spaced 16 inches on center (o.c) can span a maximum distance of 13 feet 5 inches. Another option are 2 X 8 rafters spaced 24 inches o.c.
A 50psf snow load 2×6 @ 16″ oc can span around 10 feet.
2×6’s should never be used for joists, ever. Tossing a hot tub on top of them is a really bad idea. If budget is too tight to do things properly, then it should not be done at all (tear down the existing deck ). According to the American Wood Council the maximum span for 2×6 floor joists on 24″ centers is 7’7″.
2×6 is thicker and is stronger, but is also more expensive. Spacing between deck boards provide a few critical functions. The primary function is to drain water from the deck. Gaps that are narrow (1/8”), can catch debris, specifically on top of the joists, and can be difficult to clean out.
A standard deck will need four footings parallel to the house, but they will need to be temporarily braced by 6 inch-by-6 inch posts. Using doubled boards, you will then need to build beams on the top row of the posts to frame the edges of the deck. These must be topped with adjustable post caps.
In short there’s no one right answer to “how much can my deck hold?” However, one rule of thumb to keep in mind while answering the question is that the answer commonly is that if a deck is properly designed, it’s built to hold 50 lbs. per square foot.
When supporting joists that span 12 feet with no overhang beyond the beam, a double ply beam can span in feet a value equal to its depth in inches. For instance, a double 2×12 beam can span 12 feet; a (2) 2×10 can span 10 feet and so on.
Considering that you will use 2x4s for the joists, at a 12″ span, you cannot make the deck larger than 8’x8′. As you will see in this project, this light construction doesn’t require complex tools or carpentry techniques, so any person with basic skills can get the job done in just a weekend.
For roofs that won’t experience heavy snow loads, a gable roof can span up to 22′ with 2×4 rafters. For roofs that will experience heavy snow or wind and will span the same distance, use 2×6 rafters. If you have a simple gable shed roof, then using 2×4 rafters makes more sense unless you have a very large shed.