I'm working on hanging an Ikea Lisabo shelf. Earlier, I put one on a wall without much trouble using snap toggles, which are great. However, this second shelf, on a different wall, is giving me trouble.
The wall seems to be drywall, or possibly plaster, over plywood, followed by a small air gap, and then brick. The picture below shows a hole I drilled, illuminated by a flashlight. Unfortunately, the air gap between the plywood and then brick is insufficient to snap snap toggles into place; they require 1⅞" inch clearance in which to rotate flat after being inserted into the hole. I bought 3/16" standard spring-loaded toggle bolts, hoping they would require less clearance. I was able to get one of the two required toggles to open in the air gap, but the other won't — it appears that the distance between the plywood and the brick wall isn't uniform, and there's not enough clearance on the left hole.
Now I'm wondering what to do next. Two ideas I've considered:
- Put some type of mounts into the brick behind the hollow wall. I've never mounted anything to brick or cement, so I'm not really sure whether this would work. I'm also worried that the approximately 2" of distance between the brick wall and the shelf could severely reduce the shelf's capacity, because the screw or bolt will be unsupported for that length.
- Drive large-ish wood screws through the drywall/plaster and into the wood behind, making sure they're short enough that they don't strike the bricks. My two concerns here are whether two wood screws would be strong enough, and also whether the wood backing is thick enough to provide adequate support. I don't think it's simply plaster laths, as it seems too thick for that, but I'm not certain.
How should I proceed in mounting the shelves?
I made an attempt to find duplicate questions before asking this one, but none seem quite to match my situation. Here are a few close ones, though:
- Fixing TV on concrete behind drywall
This is perhaps closest. It doesn't offer a conclusive answer about how big a gap between the brick and the drywall is too big, though.
- How can I fix a cabinet to plasterboard with brick wall behind?
- What is up with this wall, and what is the right way to hang something on it?