2x4 Rafters To 2x8 Floor Joists

Floor beam table.

2x4 rafters to 2x8 floor joists.

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. Most new construction uses 2 by 8 lumber for joists although 2 by 6. Use your common sense when deciding how many fasteners are needed. 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.

Hem fir 2 joists with a live dead load of 40 10 psf. Span calculator for wood joists and rafters also available for the android os. The heavier the load the closer together the. However when running spf 2 6 floor joists into the floor joist calculator referenced above you get a maximum span of 9 feet 8 inches with a minimum bearing length of 3 inches at each end on 12 centers.

Splitting the wood does no good. If you want to put down flooring in your attic and want more insulation underneath that floor then you need to increase your joist size. Also available for the android os. Joist span and spacing is set by your local building code.

While every effort has been made to insure the accuracy of the information presented and special effort has been made to assure that the information reflects the state of the art neither the west coast lumber inspection bureau the american wood council nor its members assume any responsibility for any particular design prepared from this online span calculator. In this case the framer used 9 8d nails on each side of splice which is adequate in this case. Floor joist table joist size joist spacing maximum span 2 x 6. Measure the width and length of the existing joist.

A 9 2 2x4 2 2x6 2 2x6 2 2x6 2 2x8 2 2x10 2 2x10 2 2x12 2 2x12 n 10. Pictured at left is a diagram of some recommend prescriptive repair techniques for floor joists. The rule of thumb is 6 foot span with a 2 6 on 16 centers. This a rough guideline.

For example in the rafter span table below the highlighted cell in the 40 live load table indicates that 2 x 8 southern yellow pine joists that have a grade of 2 that are spaced 24 apart can have a maximum span of 10 feet 3 inches 10 3 if designing for a live load of 40 lbs ft 2. In this case the framer just needed a longer rafter.