Double 2x8 Floor Joist Span

Floor joist span tables for various sizes and species of wood.

Double 2x8 floor joist span.

While most residential construction uses 2x8 joists with 16 inch spacing there are many other factors you need to consider when determining the proper joist span length. When building a house or even a deck it is important to confirm you have the correct joist sizes spans and spacing before you get started. Joist span and spacing is set by your local building code. The current floor joists are 2x8 and span the 24 feet but there is a wall mid way.

A 2 2x10 can span 10 feet and so on. Dimensional lumber deck beam span chart. Or do we need to do a header to support the second level. 1 psf lb f ft 2 47 88 n m 2.

Maximum floor joist span for no. A double 2x12 beam can span 12 feet. Hem fir 2 joists with a live dead load of 40 10 psf. If we were to double up the joists to add additional support would that work.

Spans in this table were derived from the irc table r502 3 1 2 design criteria. Nope if you put 2x4 and 2x8 in a span calculator it is not 4 times the distance. If you instead make them one on top of the other so 2x4 becomes 2x8 it is 4 times as strong. We have steel columns in the basement supporting the house.

The point was that depth of joists beams does more than height. 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. Joist span table use these tables to determine floor joist spans based on grade of lumber size of joist floor joist spacing and a live load of 30 lbs ft 2 or 40 lbs ft 2 these tables can also be used to determine deck joist span. Also available for the android os.

2 grade of douglas fir are indicated below. So can it span twice the distance. Span calculator for wood joists and rafters also available for the android os. Dead load weight of structure and fixed loads 10 lbs ft 2.

These are 16 on center. Beam and joist span tables built up wood floor beams supporting one floor in a house maximum spans for uniformly distributed loads species and grade supported built up beam size joist length 3 2x8 4 2x8 3 2x10 4 2x10 3 2x12 4 2x12 8 9 8 11 2 11 10 13 8 13 8 15 10 10 8 8 10 0 10 7 12 2 12 3 14 2.