Attic Joists Live Load

Span calculator for wood joists and rafters also available for the android os.

Attic joists live load. Use six 10d nails with plywood gussets or six 16d nails with 2x4s half into each 2x6 joist. Standard joist spacing for the installation of attic flooring materials is 16 inches on center oc meaning the distance from the center of one joist to the center of the next joist is 16 inches. Use span tables for progressively heavier loads until you find the limits of your floor. 2attic loads may be included in the floor live load but a 10 psf attic load is typically used only to size ceiling joists adequately for access purposes.

In this case your joists are adequate to support a 30 psf live load and 10 psf dead load. If the attic joists are not adequate one way to strengthen the floor for live loads is to sister the old joists. There are also factors such as deflection elasticity and wood species that come in to play. An inaccessible attic space on the other hand might have a live load of only 20 psf.

In the case of 2x6 joists you can pair them up with additional 2x6 joists by nailing them together. Consult local building codes for snow load capacity and reference the span tables for joists and rafters published by the american wood council awc. A room used solely for sleeping might need to carry only 30 psf whereas a garage floor over a basement would need 50 psf or higher. Live load psf dead load psf span calculator for wood joists and rafters available for the iphone.

The span table for a 30 psf live load 10psf dead load floor indicates a required fb value of 1 315 and a minimum e value of 1 800 000. Loads should be determined in accordance with this chapter. Attic ceiling joists with limited storage. First floor live loads have higher requirements than second floor live loads 40 pounds per square foot vs.

Strengthening attic joists for live loads by sistering. Sistering is the process of adding a new joist next to each existing joist. However if the attic is intended for storage the attic live load or some portion should also be considered for the design of.