Lumber Span Tables 2x4 Flat Roof Rafters

Limited to span in inches divided by 360.

Lumber span tables 2x4 flat roof rafters.

Also available for the android os. Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no. 2 are indicated below. Visit the roof framing page for more information on cutting roof rafters and visit the roof pitch calculator for determining rafter lengths based on rise and run.

Permitted for intermediate spans and design values. Strength live load of 30 psf plus dead load of 10 psf determines the required bending design value. Rafter span tables use these tables to determine lengths sizes and spacing of rafters based on a variety of factors such as species load grade spacing and pitch. Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters.

Dead load weight of structure and fixed loads 15 lbs ft 2. Most roof framing is 24 on center and you can still build sheds up to 14 with 2 4 rafters at 24 on center. Maximum rafter spans for a patio roof in areas with mild climates patio roofs are generally designed for loads of 30 psf pounds per square foot. For heavy loads 2x4s can span up to 5.

Span calculator for wood joists and rafters also available for the android os. Tables w 1 and w 2 of design values for joists and rafters a supplement to these span tables provide such values for the most commonly used. Simplified maximum span tables for selected visual and mechanical grades of southern pine lumber in sizes 2 4 thru 2 12. Deflection for 30 psf live load.

Span tables for jois ts and rafters american wood council 4 span tables for joists and rafters american wood council design criteria. 1 psf lb f ft 2 47 88 n m 2. 1 ft 0 3048 m. 2 4 rafters can span up to 7.

Live load is weight of furniture wind snow and more. For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements. Spacing your 2 4 shed rafters at 24 on center limits the width of your roof. For light load roofs 24 o c.

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. Rafter spans can be extended slightly beyond what the rafter tables suggest when there is a cantelever extending beyond the supporting wall.