Weight Limit Attic

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.

Weight limit attic.

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. If the attic has the potential to become a regular living space talk with a contractor about adding a fixed stairway. Of stuff on it. The joists are what support the weight.

All weight hanging from the truss has to be added to the existing dead load. Make sure items are spaced so that the weight is evenly distributed over the chords. An uninhabitable attic designed for limited storage can handle 20 pounds per square foot live load. The dead load on the bottom chord of a truss varies with the weight of materials attached to it such as drywall on the ceiling.

Spacing between each beam is 14 4. Scrap of plywood over the chords and set about 40 lbs. Is a safe estimate. Observing the weight rating.

Length of the beams. A typical load is 5 and 10 pounds per square foot. I put the floor in about twelve years ago and can t remember. That means you could lay a 2 x 4 ft.

In the example the joists have a spacing of 16 inches and a span of 11 feet 2 inches. Size of the beams supporting attic floor. I m guessing you don t have the plans and don t know what live load the attic was designed for. Next consult a span table to cross reference the spacing and span to find the required fb value for that table s load limits.

So if your ceiling is unfinished you have some excess carrying capacity up there. If the total weight exceeds the load limit of the truss then the truss is compromised. An uninhabitable attic not designed for storage can handle a 10 pounds per square foot live load. This is because the ladder is simply not strong enough to support any more weight and you are putting unreasonable pressure on the attic access ladders every time you break the weight limit.