Garage Shelving Question

Here's a more natural version: --- That "just bolt into the concrete anywhere" advice doesn't really hold up once there's a lined wall in the way. You've got plasterboard, then a void with insulation, then the block behind — so if you drive a screw through all that into the masonry, the board isn't doing anything structural, it's just sat in the middle of a gap. Under load it crushes and the bracket ends up rocking loose. Your instinct was right, plasterboard can't carry a point load on its own. For normal shelving the answer is much simpler than people make out: fix into the studs. Find your centres (usually 400 or 600mm), screw the brackets straight into the timber, job done. If your bracket positions don't line up with a stud, don't just wing it into bare board — add a noggin or, easier still, run a horizontal batten across the wall screwed into every stud it crosses, then hang your brackets/shelves off that. Gives you way more flexibility on spacing too. The only time you actually need to go through into the block is for something genuinely heavy — engine hoist, wall-mounted boiler, that kind of thing. For that you'd use sleeved frame fixings (Rawlplug, Index, Timco all do them) which bridge the cavity properly so the load isn't relying on the board at all. Worth measuring your exact cavity depth first so you get the right sleeve length. For garage shelving though, honestly just go studs or a ledger board, you don't need to overcomplicate it.

Best to fix into timbers where possible, if not though appropriate wall fixings with spacers would work well if correct spec and used properly

The concrete block wall is what should ultimately support the weight, not the plasterboard. If you're putting up lightweight shelves for things like paint tins or small tools, fixing into the timber studs can be perfectly adequate, provided the brackets line up with the studs. However, if you're planning to store heavier items, it's best to fix through the plasterboard and insulation into the concrete block behind using suitable concrete screws or frame fixings. A common approach is to first fix a treated timber batten securely to the block wall with concrete fixings, then attach your shelf brackets to the batten. This spreads the load across multiple fixings, makes positioning the brackets much easier, and provides a very strong fixing for garage shelving. One thing to be aware of is the depth of the cavity between the plasterboard and the block wall. If there's a significant gap, you'll want to use spacers or sleeves so that tightening the fixings doesn't compress or damage the plasterboard. Done correctly, this will give you a much stronger and more durable installation than relying on plasterboard fixings alone.