Maximum Roof Span For 2x4

2 4 rafters can span up to 7.

Maximum roof span for 2x4.

Spaced sheathing or 1x boards may be reduced slightly. I used your formula backwards to calculate the max psf of a ceiling with 2x4 ceiling joists spanning 12 and spaced 24 o c. Most roof framing is 24 on center and you can still build sheds up to 14 with 2 4 rafters at 24 on center. Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no.

For heavy loads 2x4s can span up to 5. 1 psf lb f ft 2 47 88 n m 2. 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. 2 are indicated below.

Assuming the fb of hemfir is maxxed at 1275 psi and i came up with 12 737 psf. 2x4f 2000psif 1100psie 1 8x10 2x6f 1750 psi f 950 psi f 1900 psi e 1 8x10. Allowable spans for 2x4 top chord trusses using sheathing other than plywood e g. For light load roofs 24 o c.

Maximum and use lumber properties as follows. Live load is weight of furniture wind snow and more. Span calculator for wood joists and rafters also available for the android os. 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.

Dead load weight of structure and fixed loads 15 lbs ft 2. Also available for the android os.