How Wide Are Floor Joists In General

I plan to space i joists 12 o c across the width of 28ft for a total of 26 i joists.

How wide are floor joists in general.

In the past 2x4s or 2x6s were sometimes used as floor joists. Advice i ve been given from contractors is to screw down the plywood subfloor every 6 then use pl 400 to glue down the hardwood and then nail. In buildings with basements the first level of floor joists serves the same purpose. The width of the homes varies.

But larger is not always better when builders are constructing a home or adding a room addition. The typical floor layout is that there s a staircase on one side along the length of the party wall and the joists go all the way across. I m using 11 7 8 i josits. When possible position floor joists with any crook in the board facing up so the weight on the joist will tend to straighten it out.

In building constructions the term joist refers to a horizontal framing member that is the primary structural element of a floor or ceiling frame. After joists are installed plywood subflooring and or drywall are fastened to the joists to complete the structural floor or ceiling. And the joists are either 3x8 3x10 or 3x12. Joists span across the tops of load bearing walls and may be supported at mid span by a beam or other member.

So the house dimensions will now be 24 x 13. The big boxes are spec ing boise cascade i joists. 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. They re either 18 feet 20 feet or maybe 25 feet wide depending on how the lots were subdivided says dunne.

This size is no longer acceptable when framing a structure. 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. See the image below for an example of joists spaced 16 on center 16 o c. Since the example house we are designing for is 12 feet wide we need to find in the floor joist span table a joist size and centering that can span 12 or wider.

The material placed on top of the floor joists may be plywood oriented strand board osb or particle board. The homeowner says they want to feel the floor as solid as possible with as little hint of deflection as possible. In general practice 2x8s 2x10s or 2x12s are used when framing a raised floor instead. Any large knots found near the edge of the board should face up as well so the weak wood of the knot will be compressed rather than stressed.

The structure in question here is 20ft 6 long x 28ft wide. Let s expand our house beyond that 17 2 span capability to 24 feet wide. In any case the joists have glue spread on them and then the 4 x 8 panels of sub flooring are nailed in place. For more information the hardwood is 3 4 x 5 solid white oak.