Attic Storage Load Limit
Dead load of first floor ceiling plastered 20 lbs.
Attic storage load limit. Is a safe estimate. 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. Access to attic storage. 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.
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. 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. Of stuff on it. 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.
Of floor area dead load of partitions 20 lbs. That means you could lay a 2 x 4 ft. Storage space dead load of partitions 20 lbs. Scrap of plywood over the chords and set about 40 lbs.
Of floor area dead load on second floor 20 lbs. If the attic has the potential to become a regular living space talk with a contractor about adding a fixed stairway. Dead load of first floor ceiling not plastered 10 lbs. Live load on second floor local requirements.
Make sure items are spaced so that the weight is evenly distributed over the chords.