Attic Storage Load Limit

Scrap of plywood over the chords and set about 40 lbs.

Attic storage load limit.

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. That means you could lay a 2 x 4 ft. Access to attic storage. Of floor area dead load of partitions 20 lbs.

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. Dead load of first floor ceiling not plastered 10 lbs. Make sure items are spaced so that the weight is evenly distributed over the chords. 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.

Dead load of first floor ceiling plastered 20 lbs. If you want to use your attic on a regular basis or to store large items you may need to enlarge the access opening and install an access ladder or drop down stairs. Dead load of attic floor when floored 20 lbs. Of stuff on it.

Of floor area dead load on second floor 20 lbs. Is a safe estimate. 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. Live load on second floor local requirements.

So if your ceiling is unfinished you have some excess carrying capacity up there.