4x8 Floor Joist Span Chart

You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths.

4x8 floor joist span chart. The table excerpt above is simply a sample and may not be valid for your region. Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads. Joist span and spacing is set by your local building code. 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.

Looking at this table you will see there is a choice in the size of floor joist 2 x 6 2 x 8 2 x 10 or 2 x 12 and there is a choice in the joist spacing 12 16 or 14. Sample floor joist span table. 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. Floor joist span tables for various sizes and species of wood.

9 16 tji joists design properties 6 floor span and load tables 7 8 tips for preventing floor noise 8 allowable holes 9 cantilevers 10 11 roof span and load tables 12 13. Fire safe construction 3 floor performance and tj pro rating 4 5 section 1. The floor joist spacing is the distance between the centers. 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.