Attic Joist Span Tables

Ceiling joist spans for common lumber species uninhabitable attics with limited storage live load 20 psf l δ 240 check sources for availability of lumber in lengths greater than 20 feet.

Attic joist span tables.

Ceiling joists of the first floor of a two story structure often serve as floor joists for the second floor. Builders generally use pre calculated tables to tell them appropriate joist spans for each lumber species size. Timber floor joists shall be adequate for the spans and loads and be correctly installed. Straight line interpolation shall be permitted for intermediate spans and design values.

Joist span tables use these tables to determine lengths sizes and spacing of ceiling joists. Roof span and load tables 12 13 framing connectors 14 15 section 2. Joist span tables. Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters.

Where the tables do not apply or where there are concentrated loads floor joists should be designed by an engineer in accordance with technical requirement r5. View joist rafter tables. If this is the case with your structure use the floor joist table to determine maximum joist length load. An inaccessible attic space on the other hand might have a live load of only 20 psf.

You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths. Design information for all joists tji joist floor framing 24. The calculated spans assume fully supported members properly sheathed and nailed on the top edge of the joist or rafter. Joist and rafter span tables.

Simplified maximum span tables for selected visual and mechanical grades of southern pine lumber in sizes 2 4 thru 2 12. Span calculator for wood joists and rafters also available for the android os. Joist span refers to the measurement covered by the joist between supporting structures such as beams or foundation walls. Solid timber joist sizes are provided in the bs 8103 3 span tables.

1 inch 25 4 mm 1 foot 304 8 mm 1 pound per square foot 0 0479kpa. Span exceeds 26 feet in length. Also available for the android os. Span tables use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads.