Calculating the size of the floor joists you need when building a home or an addition is not a complex situation as we have provided a chart that will allow you to make your selection.
Note: Always check with your local building department to ensure that your choice of floor joist size and material meets their requirements.
Four charts are provided:
- 40 psf and 12″ spacing
- 40 psf and 16″ spacing
- 30 psf and 12″ spacing
- 30 psf and 16″ spacing


