That's a great and practical question! It really depends on the bin's material and construction, but there's no single universal number. Most standard 32- to 44-gallon plastic bins from a big-box store are designed for typical household bagged waste, not for heavy, dense loads. Their bottoms can often start to crack or fail under sustained loads of 40-60 pounds, especially if the weight is concentrated (like from construction debris or wet soil).
Think of it this way: the bin is designed to hold the *volume* of the bags, not necessarily extreme *weight*. Thin, brittle plastic in cheaper bins is the main culprit. Factors like sun exposure (UV degradation), freezing temperatures making plastic brittle, and an uneven surface stressing the base all significantly reduce that capacity.
For heavier loads, you need to look for bins labeled "heavy-duty" or "contractor grade," often made from thicker, cross-linked polyethylene. These can often handle 100+ pounds. The best practice is to avoid overfilling with dense, heavy materials. If you're regularly disposing of heavy items, consider a wheeled dumpster-style can or making more frequent, lighter trips. Listen to your bin—if the bottom is visibly flexing or creaking, it's a clear sign you're pushing its limits.