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.
Weight limit attic.
Length of the beams.
A typical load is 5 and 10 pounds per square foot.
It is vital to observe the weight rating and make sure that you comply with it at all times.
Make sure items are spaced so that the weight is evenly distributed over the chords.
The joists are what support the weight.
Of stuff on it.
Hard to measure since i already have a lot of stuff in the attic but i think that they are about 24 ft long.
In the example the joists have a spacing of 16 inches and a span of 11 feet 2 inches.
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.
An uninhabitable attic not designed for storage can handle a 10 pounds per square foot live load.
If the total weight exceeds the load limit of the truss then the truss is compromised.
So if your ceiling is unfinished you have some excess carrying capacity up there.
Next consult a span table to cross reference the spacing and span to find the required fb value for that table s load limits.
All weight hanging from the truss has to be added to the existing dead load.
I m guessing you don t have the plans and don t know what live load the attic was designed for.
Scrap of plywood over the chords and set about 40 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.
Size of the beams supporting attic floor.
Observing the weight rating.
Is a safe estimate.
That means you could lay a 2 x 4 ft.
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.
Access to attic storage.
Spacing between each beam is 14 4.