Floor Joist 2 X 10 Or 2 X 8

Common sense tells you that large floor joists can carry more load and spacing joists closer together also increases the load bearing capacity of a floor.

Floor joist 2 x 10 or 2 x 8.

Douglas fir 2 by 10 joists graded as structural select allows joist spans up to 21 feet for a live load of 30 pounds per square foot when spaced 12 inches apart 19 feet 1 inch for 16 inch spacing and 16 feet 8 inches for 24 inch spacing. Even when using the strongest wood to build joists for a deck that wood is still subject to the elements and can bend bow or warp with time. Steel joists such as trex elevations are machine made making each joist an identical twin. When framing openings use header and trimmer joists.

Depending on the length of the home and the number of floor joists the additional cost for the heavier floor joists may not be very substantial. Maximum end notches for 2 x 8 2 x 10 and 2 x 12 respectively are 1 13 16 2 5 16 and 2 13 16. The extra two inches of vertical distance when a floor is framed with 2 x 10 joists rather than 2 x 12s can be quite important for example. Spaced o c species grade 30 lb ft 2.

But larger is not always better when builders are constructing a home or adding a room addition. Treated lumber is critical to the performance and safety of an entire system or construction such as deck joists beams and ledger. Steel joists offer a stronger straighter and potentially safer alternative to wood. I would use at least 2 2 x 8 sandwiched together if not 2 x 10 or 2 x 12.

For example in the joist span table below the highlighted cell shows that 2 x 8 southern yellow pine joists that have a grade of 2 and are spaced 24 apart can have a maximum span of 10 feet 3 inches 10 3 if designing for a live load of 40 lbs ft 2. 2 x 8 joists spanning only 8 feet is more than enough. This will give you a much stronger beam. Must use ground contact pressure treated lumber where lumber is at risk for poor air circulation less than six inches from the ground or has poor or no water drainage below the structure.

Scn smooth shank hdg connector nail 600 pack. A live load of 60 pounds per square foot demands more support and shorter spans. Use an approved hanger or a 2 x 2 ledger strip on flush beams for spans greater than 12.