Attic Dead Load

Live load on attic floor local requirements.

Attic dead load.

Dead loads are things that do not move. 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. Most houses attics are built without flooring and are not designed to carry. 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. B the top chord live include snow load as a live load and bottom chord live load. 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. C determine the total load and proper load duration.

Unlike the trussed roof live load and dead load of the rafters and ceiling joists must be accounted for as separate systems. Dead load of roof of wood shingle construction 10 lbs. Psf ceiling load for a c ducts plumbing and wiring the attic space is considered uninhabitable but will be used for storage. As a result the live load dead load and distribution of forces are different.

Your attic floor was probably built with dead loads in mind. The ceiling load may include items like drywall ducts recessed lights bathroom fans and attic insulation. 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. Dead load of attic floor when floored 20 lbs.

When used for storage only dead load of attic floor not floored 10 lbs. Live loads are people and animals and tangentially the things used by people. 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.