You’ve got a shelf, a drill, and a wall. You buy a pack of screws that look about right. You drill a hole, push the screw in, and… the whole thing spins uselessly. The shelf falls. The plaster crumbles. Now you’ve got a hole to patch and a trip back to the hardware store.
I’ve done that. Most DIYers have. The problem isn’t the screw — it’s the fixing. Fixings are the bits that actually grip the wall. Screws just hold your shelf. If the fixing fails, nothing else matters.
This article covers what fixings are, which ones work for which wall, and the mistakes that cost you time and money. No fluff. Just the specs and logic you need to get it right the first time.
What Are Fixings? The Part That Actually Holds Your Load
A fixing is any hardware that creates a secure connection between a screw and the building material. Think of it as the middleman. The screw threads into the fixing, and the fixing expands or locks into the wall.
Without a fixing, a screw in plasterboard or brick will either spin free or crack the material. Fixings solve that by distributing the load and gripping the substrate.
Common types include:
- Wall plugs (plastic anchors) — the most common. You drill a hole, push the plug in, then screw into it. The plug expands against the wall.
- Toggle bolts — spring-loaded wings that open behind hollow walls. Used for heavier loads on drywall.
- Masonry anchors — metal sleeves or shields for brick, concrete, or stone. Often require a hammer and a specific torque.
- Self-drilling anchors — screw directly into plasterboard without a pilot hole. Quick, but limited load capacity.
Each type solves a specific problem. The wrong fixing for your wall is a failure waiting to happen.
Why Fixings Exist
Building materials fall into two categories: solid (brick, concrete, stone) and hollow (plasterboard, drywall, hollow block). Solid materials are dense and brittle. Screwing directly into them cracks the surface. Hollow materials have no solid core for a screw to bite into. Fixings bridge that gap.
A standard 6mm wall plug in brick can hold roughly 20-30kg in shear load. The same plug in plasterboard might hold 5kg if you’re lucky. The fixing doesn’t change — the wall does.
How to Match Fixings to Your Wall Type
This is where most people get it wrong. They buy a universal pack of fixings and assume it works everywhere. It doesn’t. Here’s the breakdown by wall type.
Plasterboard / Drywall
Plasterboard is gypsum sandwiched between paper. It’s soft. Standard wall plugs will spin and tear the paper.
For loads under 5kg (a small mirror, a towel ring), use self-drilling plasterboard anchors. The Fischer UX 6×30 is a solid choice — about $0.15 per piece, rated to 10kg in 12.5mm board. Screw it in with a Phillips bit. No pilot hole needed.
For 5-15kg (a medium shelf, a coat rack), use toggle bolts. The TOGGLER Snoggle (about $0.50 each) has spring-loaded wings that open behind the board. They spread the load across a wider area. I’ve hung a 12kg mirror with two of these. Rock solid.
For anything over 15kg (a wall cabinet, a TV mount), you need to hit a stud. No fixing in plasterboard alone will safely hold 30kg. Use a stud finder, mark the studs, and screw directly into the wood with 50mm wood screws.
Brick and Concrete
Solid walls are strong but brittle. You need a masonry bit and a hammer drill. The fixing must expand tightly inside the hole.
Standard nylon wall plugs (like Rawlplug R-KX, 6x30mm, about $0.10 each) work for most jobs up to 30kg. Drill the hole exactly to the plug diameter (6mm for a 6mm plug). Clean out the dust. Push the plug in flush. Then screw in.
For heavy loads (a gate, a large shelf bracket) use metal expansion anchors. The Fischer Bolts & Sleeves FBS 8 (about $0.80 each) handle 50kg+ in concrete. They expand a metal sleeve against the hole wall. You need a spanner to tighten them.
One mistake: drilling too deep or too shallow. The plug needs full contact. If it’s loose, it won’t expand properly. If it’s too deep, the screw won’t reach the expanding part.
Hollow Block and Aerated Concrete
Hollow block (like Hebel or lightweight concrete) is tricky. It’s soft but has cavities. Standard plugs often fall into the void.
Use hollow wall anchors or chemical anchors. The Fischer DuoPower (about $0.30 each) has two zones — one for solid material, one that folds and grips in cavities. It’s the best all-rounder I’ve tested for mixed substrates.
For heavier loads in aerated concrete, use a resin anchor kit. Clean the hole, inject resin, insert a threaded rod. It bonds chemically. Holds over 100kg when done right. More expensive (about $15 for a kit with 10 anchors) but necessary for structural work.
Three Fixing Mistakes That Cost You Time and Money
I’ve made all of these. Each one meant patching a hole and starting over.
Mistake 1: Using the Wrong Drill Bit Size
Wall plugs have a recommended drill bit diameter printed on the pack. A 6mm plug needs a 6mm bit. Using a 5mm bit means the plug won’t go in. Using a 7mm bit means the plug spins freely and never expands. The fixing is useless.
Check the pack. Use a bit size that matches exactly. For masonry, use a carbide-tipped bit. For plasterboard, a standard HSS bit works fine.
Mistake 2: Not Cleaning the Hole
Drilling creates dust. If you push a plug into a hole full of brick dust, the plug sits on a layer of grit. It can’t grip the solid wall. The screw tightens, the plug shifts, and the load pulls it out.
Blow the dust out. Use a vacuum nozzle or a puff of air from your mouth. Then insert the plug. It should slide in with light resistance, not fall in or require a hammer.
Mistake 3: Over-Tightening the Screw
You screw until it feels tight. Then you give it one more turn. The plug spins. The wall cracks. The fixing is destroyed.
Stop when the screw head is flush with the surface and you feel resistance. On plasterboard, stop even earlier — the board can crush. On brick, one or two turns after the plug starts expanding is enough. Hand-tight plus a quarter turn is a good rule for most nylon plugs.
When NOT to Use Fixings — Alternatives That Work Better
Fixings aren’t always the answer. Sometimes the right tool is something else entirely.
When to Screw Directly Into Wood
If you have wooden studs, joists, or battens, don’t use a fixing. Screw directly into the wood. A 4.5mm x 50mm wood screw into a stud will hold more weight than any plug in plasterboard. Use a countersink bit to avoid splitting the wood.
To find studs, use a magnetic stud finder (about $10 on Amazon). It detects the nails in the stud. Mark the center, drill a pilot hole, and screw in.
When to Use Adhesive Instead
For very light items (a small hook, a cable clip), adhesive strips or mounting tape are faster and leave no holes. 3M Command Strips hold up to 2kg per strip. They’re removable without damaging paint. No drill, no fixing.
For medium loads on smooth surfaces (tile, glass), use construction adhesive like Liquid Nails. Apply a bead, press the bracket on, and let it cure for 24 hours. It holds 20kg+ on tile. You can’t remove it easily, so get the position right the first time.
When to Use Chemical Anchors
For structural loads in masonry — a handrail, a heavy gate, a balcony — mechanical fixings aren’t enough. Use a two-part epoxy resin anchor. Drill the hole, clean it thoroughly, inject the resin, and insert a threaded stud. The resin bonds to the masonry and the metal. It’s permanent. A single M10 resin anchor in concrete can hold over 200kg.
Brands like Fischer FIS V or Hilti HIT-HY 200 cost about $25 for a cartridge and 10 studs. Worth it for safety-critical work.
Quick Reference: Fixing Load Chart for Common Materials
This table summarizes safe working loads for typical fixings. These are conservative estimates for static loads (shelves, cabinets, mirrors). Dynamic loads (handrails, grab bars) need higher safety margins.
| Wall Type | Fixing Type | Max Load (kg) | Best For |
|---|---|---|---|
| Plasterboard (12.5mm) | Self-drilling anchor (Fischer UX 6×30) | 10 | Small mirrors, towel rings, light shelves |
| Plasterboard (12.5mm) | Toggle bolt (TOGGLER Snoggle) | 25 | Medium shelves, coat racks, small cabinets |
| Brick (solid) | Nylon wall plug (Rawlplug R-KX 6×30) | 30 | General shelving, curtain rails, light brackets |
| Brick / Concrete | Metal sleeve anchor (Fischer FBS 8) | 50 | Heavy shelves, gate hinges, large brackets |
| Concrete (structural) | Chemical anchor (Fischer FIS V, M10) | 200+ | Handrails, structural supports, heavy gates |
| Aerated concrete | Fischer DuoPower 8×40 | 20 | General fixings in Hebel or lightweight block |
These numbers assume correct installation: clean hole, correct drill bit size, no over-tightening. Cut the load by 50% if you’re unsure about the wall construction.
How to Buy Fixings Without Overpaying
Hardware stores sell fixings in mixed packs for $5-10. Those packs are fine for small jobs. But if you’re hanging a full kitchen cabinet set or a large TV, buy individual boxes of the specific type you need.
Prices:
- Nylon wall plugs (100-pack, 6mm): $3-5 at any hardware store. The cheapest option for brick walls.
- Self-drilling plasterboard anchors (50-pack): $6-8. Worth the premium over standard plugs for drywall.
- Toggle bolts (10-pack): $8-12. More expensive per piece, but necessary for heavy loads on hollow walls.
- Chemical anchor kit (cartridge + nozzles + studs): $20-30. Only buy this if you have a specific structural job.
Don’t buy the cheapest no-name plugs from discount bins. The plastic can be brittle. Stick with Fischer, Rawlplug, or TOGGLER. They cost a few cents more per piece and won’t crack during installation.
For a typical home toolkit, buy a 100-pack of 6mm nylon plugs (Rawlplug R-KX, $4), a 50-pack of 6×30 self-drilling anchors (Fischer UX, $7), and a 10-pack of toggle bolts (TOGGLER Snoggle, $9). That covers 90% of household jobs for under $25.
One more thing: keep the fixings in a dry place. Moisture rusts metal anchors and degrades nylon over time. A sealed plastic box in your garage or utility room works fine.
