Is there a practical limit to the weight I can put on top of my kitchen cabinets?

Question

How do I get a sense of what kind of load my kitchen cabinets will hold?

The building is 12 years old, as is the kitchen fitout (we did not do the fitout ourselves so I don’t have the plans and don’t know how much it cost.) We’re in Germany, if that gives you any hints as to construction techniques or materials.

The cabinets themselves are laminated 18mm MDF; 330mm deep and each unit is 600mm wide. The wall the cabinets are hung from is reinforced concrete. I’m not exactly sure how they’re attached, but I include a picture of one of the attachment points with the blanking plate removed.

Top edge of kitchen cabinets with bottles sitting on it:

Hardware that attaches a kitchen cabinet to the wall:

Obviously failure of either the MDF or the attachment points would be catastrophic but my contention is that I’d have to hang my whole weight off the top of the cabinets and swing around a bit to make that happen. Even then it would be the MDF snapping rather than the thing pulling out from the wall.

Are there standards up to which these kinds of things must be built in Germany? If not, can anyone give me a heuristic for calculating how much (static) load they should be able to bear?

Answer 1

The best you can probably do is a proof test. It's just not possible to decide the controlling limit state without significant disassembly. What's the anchor embedment in the concrete, for instance?

To conduct a proof test, decide the capacity that you want (obviously this must be a reasonable value), multiply it by 1.2, 1.25, 1.5, or some other reasonable safety factor. Now apply this load to the cabinets to test them. The strength is probably a function of eccentricity from the wall, so apply the load at a reasonable offset from the back of the cabinets. I would do something like 75% of the cabinet thickness measured from the back.

Note that the US's wood design code has a "load duration factor" of 1.6 for 10 minute load durations (like gusting from major wind loads or from earthquakes). For 10 year load durations, it's 1.0. This implies that wood (sawn lumber, not MDF) has a short load-duration strength of 1.6/1.0 = 1.6 of its long load-duration strength. A proof test has a short load-duration. You should therefore divide your proof test's established capacity by 1.6 to get a long load-duration capacity, where I assume the long load-duration capacity is more appropriate for your cabinets.

The cabinets are probably connected to each other, so it might be a good idea to uncouple one of them from the others, test only the one, and then assume that its established capacity applies to the other cabinets as well.

If the controlling limit state is something like the bolt tearing out of the wall, then a proof test failure won't damage the cabinet. That's only if you construct something to prevent the cabinet from falling, however, so you might do something to catch the cabinet in case it falls.