I want to fix a cabinet to a bathroom wall. The wall is 710mm wide and has a single stud slightly off-centre, about 270mm from the right, but which is too near the middle to be useful for hanging the cupboard.

I was planning to use heavyweight plasterboard fixings. (I think they're also called mollies.) The pack I have says "Interset(R) 10mm Plasterboard Fixing... DRILL DIA: 10mm, FIXTURE: Max 15mm thick".

Unfortunately, when I drilled into the plasterboard, it turned out to be much thicker than I expected. I used a paperclip through the hole to help measure the thickness, and it turned out to be about 32mm thick. This seems to be much thicker than is common for plasterboard. Now I have a pair of 10mm holes in this plasterboard and I'm not sure what to do with them. I'm not sure if it's normal plasterboard, or something else. I thought perhaps it's insulated or sound-dampening.

For context, the wall in question is internal and divides one apartment from another. I understand it must have been installed in the last 10 years, since the apartment was formerly a ground-and-basement-level shop, and was converted into apartments within that time. This is in the UK.

What can I use to fix a cabinet to this thick wall? Can I get spring toggle bolts that are suitable for this thickness? How do I find suitable fixtures, since most seem to be designed for 10-15mm walls?

  • @Mazura's answer is good -- the toggles will be solid. Just know that it's a two/three person job to get the cabinet up with those fasteners. Alternately, hollow wall anchors are available for ~30mm plasterboard, but I strongly recommend getting the proper setting tool, as just putting a drill to them can sometimes end badly. Mar 6, 2015 at 15:35

1 Answer 1


It's probably double 5/8ths drywall, I'd use toggle bolts. And then washers and 3" deck screws to the stud for safety (not drywall screws), even if you're going to do all four corners with toggle bolts. There should be some one-by inside the cabinet at the top (and possibly the bottom) this is where you want your fasteners penetrating, not just through the flimsy back panel. Your local hardware store should have these:

1/4" x 4" Toggle Bolt: (tannerbolt.com)

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You can skimp on diameter if you want, but the shorter they are, the harder it's going to be to install all four at the same time. The size shown is my go-to.

Hand tighten only, or you risk stripping the tiny nut in the spreader or compromising the drywall integrity. You need to be able to feel what's going on in there; they should just be snug. Be extra careful with smaller diameter toggles as they have even wimpier nuts.

Other types of drywall fasteners are discussed here: What benefit do plasterboard drywall screws have?

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