But larger is not always better when builders are constructing a home or adding a room addition.
Maximum spacing of floor joist.
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.
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 joists are available in several depths and lengths that are sufficient for most residential and commercial building plans.
Properly spacing floor joists when framing an addition or whole structure is largely a factor of building codes.
The typical engineered floor joist is made of lumber in the shape of an i thus commonly called an i joist.
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.
The right spacing depends on the code requirements as well as the type of structure it is and the weight it.
Additionally the load that the floor needs to support is also a consideration.
There are three basic measurements used for floor joist spacing.
Joist span and spacing is set by your local building code.
The floor joist spacing is the distance between the centers of any two installed joists.
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.
I joists can be custom made for plans that require unusual sizes.
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.
Joists that are closer together can support more weight which allows the joists to span a longer distance than joists spaced further apart.
One must take into consideration the spacing of the joists and type of wood used.
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.
Click on a span to generate a full calculation you can adjust the exact span.
Floor joist span tables for various sizes and species of wood.
Spacing is measured from the center of one joist to the center of the next.
The maximum span for a 2 x 10 floor joist is up to 21 feet depending on several factors.
The maximum span distance for 12 inch spacing is greater by as much as 30 percent compared to 24 inch spacing.
See the image below for an example of joists spaced 16 on center 16 o c.
This span table is to the format and methodology given in bs 5268 7 1.
There are also several floor joist sizes and types used.
