Load ratings and fixings
A shelf fails for one of two reasons: the shelf wasn't strong enough, or the wall was. This page covers both, so you can order once and fit it properly.
1. What our load ratings mean
Every shelf on this site carries a safe working load (SWL) in kilograms. Read it as: the weight the shelf will carry indefinitely when it is correctly fixed into a sound substrate, with the load spread evenly across the shelf, and not as a point load at the front edge.
- Per-shelf, not per-unit. A four-tier unit rated 30kg per shelf holds 120kg in total, not 30kg.
- Evenly distributed. Concentrating the whole rating in the outer 50mm of a floating shelf can roughly halve what it will take.
- Correctly fixed. The rating assumes every supplied fixing point is used. Leaving one bracket screw out is not a small saving.
- Our figures are the manufacturer's, not a wall guarantee. A 60kg bracket on a weak substrate is a 5kg shelf.
2. What things actually weigh
| Load | Approx. weight |
|---|---|
| Paperback books, per 300mm of shelf | 4–5 kg |
| Hardbacks, per 300mm of shelf | 7–9 kg |
| Vinyl LPs, per 300mm of shelf | 10–12 kg |
| Full 1m run of books | 15–30 kg |
| Microwave | 12–18 kg |
| Paint tins, 5L, each | 6–7 kg |
| Toolbox, loaded | 15–25 kg |
| Plant in a ceramic pot, 300mm | 8–15 kg (more after watering) |
A full metre of hardbacks is the load that catches people out. If that's the plan, choose a shelf rated at least 30kg and put a bracket or support no more than 600mm apart.
3. Know your wall before you drill
Tap it. A solid, dull thud is masonry; a hollow, drummy sound with give is plasterboard on studs or dot-and-dab. Then pick fixings accordingly.
| Wall type | Use | Realistic load per fixing |
|---|---|---|
| Solid brick or dense block | Brown/red nylon plug + 5–6mm screw, or a masonry frame fixing for heavy work | 30–60 kg+ |
| Aerated block (Thermalite/Celcon) | Purpose-made aerated-concrete fixings only — nylon plugs crumble the block | 15–30 kg |
| Plasterboard into a stud | No plug — a 5mm woodscrew at least 50mm long, biting 35mm+ into timber | 30–40 kg |
| Plasterboard, no stud | Metal spring toggle or heavy-duty hollow-wall anchor (not plastic self-drive plugs) | 10–20 kg |
| Dot-and-dab plasterboard over masonry | Long screw and plug through the void into the masonry behind — allow for the 10–40mm gap | 25–50 kg |
| Lath and plaster (pre-1930s) | Locate and fix to the timber studs; never rely on the plaster | 20–30 kg |
| Tiled surface | Tile/masonry bit, no hammer action, drill slowly through the glaze first | As the substrate behind |
Studs in a UK partition are usually at 400mm or 600mm centres. Use a detector, and check for cables and pipes before every hole — particularly directly above and below sockets and switches, where cables run vertically.
4. Bracket spacing and overhang
- Support at least every 600mm for general loads; every 400mm for books, vinyl, tools or anything you'll load solidly.
- Keep the overhang past the outer bracket to no more than 100–150mm each end.
- A bracket should support at least two thirds of the shelf depth. A 120mm bracket under a 300mm shelf will tip.
- For floating shelves, the concealed rod length must suit the shelf depth — a deep shelf on short rods will droop over time.
5. Fitting sequence that works
- Mark your height, then find the studs or confirm the substrate.
- Mark all fixing holes from the bracket or template — don't measure each one separately.
- Check level across the whole run before drilling, not bracket by bracket.
- Drill the right diameter for the fixing, to the right depth (put tape on the bit).
- Fix the brackets, recheck level, then fit the shelf.
- Load the shelf from the back forward, heaviest items nearest the wall and nearest a bracket.
- Check the fixings again after a week under load, then once a year.
6. Free-standing units and anti-tip
Tall units and shelving towers must be secured to the wall with the supplied restraint, whether or not you have children in the house. Load the bottom shelves heaviest. Never climb or stand on shelving to reach a high shelf.
7. Garage and workshop racking
Boltless racking must stand on a level floor with every beam fully seated and the safety clips fitted. Beam ratings assume the load sits on a full-width deck — not on two beams with a gap in the middle. Do not modify uprights or drill extra holes.
Not sure?
Email support@homartuk.com with your wall type, the span you need to cover and what's going on the shelf, and we'll tell you what will hold and what fixings to buy. If in doubt about the wall itself, use a qualified tradesperson — this guide is general information, not a structural assessment of your property.