Attic Dead Load

Boxes trunks suitcases etc.

Attic dead load.

When used for storage only dead load of attic floor not floored 10 lbs. Unless expressly built so an attic s joists are meant for carrying the load of the ceiling below and related elements collectively known as the dead load. 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. Since it is possible to use the attic for storage the live load of the attic floor is set at 20 psf according to code.

Design live loads will vary based on a number of factors but at a minimum 10 psf live load for attics without storage 20 psf live load with limited storage and 30 psf for habitable attics served with fixed stairs international residential code 2009 older or local codes may be different. Live load on attic floor local requirements. Most houses attics are built without flooring and are not designed to carry. The ceiling load may include items like drywall ducts recessed lights bathroom fans and attic insulation.

Dead loads are things that do not move. As a result the live load dead load and distribution of forces are different. Your allowed weight and span for a 2 x8 x12 2btr hem fir based on the info you have provided is 20 psf of dead load and 30 psf of live load with minimum bearing length of 0 68. However if the attic is intended for storage the attic live load or some portion should also be considered for the design of other elements in the load path.

To simplify you can place 20 pounds of dead load per square foot on your subfloor as long it s supported mid span. Unlike the trussed roof live load and dead load of the rafters and ceiling joists must be accounted for as separate systems. Live loads are people and animals and tangentially the things used by people. Your attic floor was probably built with dead loads in mind.

A the top and bottom chord dead load. C determine the total load and proper load duration. Dead load of roof of wood shingle construction 10 lbs.