The table below shows the maximum span for a floor joist with the following designations.
Floor joists for 13 foot span.
Douglas fir larch lumber species no.
Maximum floor joist span for no.
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.
Dead load is the weight of the structure and any fixed items.
The illustrations one for cantilever joists and one for flush rim beam hung joists point out where joist span measurements are taken from the saddle of the ledger mounted joist hanger to the center of a dropped beam or saddle of the.
Also available for the android os.
This chart is for basic reference only.
Calculated allowable properties are based upon aisi s100 07 north american specification for the design of cold formed steel structural members.
For example you can span a 1 grade no knots southern yellow pine a greater distance than a 2 grade with knots southern yellow pine.
Span entries are listed for 2 6 through 2 12 joists and 12 in 16 in and 24 in.
Our joist span charts are for wood joists with a maximum dead load of 10 pounds per square foot and a live load of 40 pounds per square foot.
Live load is weight of furniture wind snow and more.
Let s start with a simple very small house 12 feet wide by 13 feet long.
Our floor joist beam can span a maximum of 13.
Table notes spans are based upon continuous support of compression flange over the full length of the joist.
If you have any questions.
The house will have a gable roof and will be framed with wood studs.
Live load represents the weight of furniture snow etc.
Span calculator for wood joists and rafters also available for the android os.
But larger is not always better when builders are constructing a home or adding a room addition.
So we now have adequately sized floor joists and an adequately sized floor joist beam for our 24 x 13 house.
1 psf lb f ft 2 47 88 n m 2.
The lengths and sizes of joists vary depending on the species and quality of the lumber used.
Floor joist span tables for various sizes and species of wood.
Dead load weight of structure and fixed loads 10 lbs ft 2.
For two equal spans the listed span is the center to center distance from either end to the center support.
2 lumber grade all joists are bridged sample floor joist span.
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.
1 ft 0 3048 m.
2 grade of douglas fir are indicated below.
