I've lost count of how many shelves I've reattached that fell off because someone used the wrong fixings. Here's how to get it right first time.
Know Your Wall Type First
Everything starts with identifying what you're drilling into.
Quick test:
- Knock on it: Hollow = plasterboard. Solid = brick/block/stone
- Drill test: Stop after 30mm. Red dust = brick. Grey = block. White = plasterboard. Yellow/sandy = stone
- Look around: New builds are mostly plasterboard. Victorian houses are usually solid walls.
Solid Walls: Brick, Block & Stone
Standard Plastic Rawlplugs
The classic choice for solid walls.
| Colour | Screw Size | Drill Bit | Use For |
|---|---|---|---|
| Yellow | 3-3.5mm | 5mm | Very light fixings |
| Red | 4-5mm | 6mm | Light to medium (most things) |
| Brown | 5-6mm | 7mm | Heavy items |
| Blue | 8-10mm | 10mm | Very heavy |
How they work: You drill a hole, push the plug in, and the screw expands it to grip the masonry.
Tips:
- Hole should be same diameter as plug (snug fit)
- Drill into brick, not mortar (brick is stronger)
- Plug should be slightly below surface, not sticking out
- Hole depth = plug length + 10mm
For Heavy Loads: Shield Anchors
When you're hanging something really heavy (boiler, TV bracket, heavy shelving), shield anchors are better than plastic plugs.
Types:
- Bolt projecting: Bolt sticks out ready for a nut
- Hook/eye: Integrated hanging point
- Internally threaded: Screw bolts into them
How they work: The metal shield expands against the sides of the hole when you tighten.
Load rating: Single M8 shield anchor in brick = 100kg+
Plasterboard (Stud Walls)
This is where most people go wrong. Standard rawlplugs DO NOT work in plasterboard - there's nothing for them to grip.
Option 1: Hit the Studs
If possible, always fix into the timber studs behind plasterboard.
- Finding studs: Use a stud finder, or knock along the wall listening for solid vs hollow
- Typical spacing: 400mm or 600mm apart
- Fixings: Standard wood screws (50mm+). No plugs needed.
This is the strongest option for heavy items.
Option 2: Cavity Fixings
When you can't hit a stud, use fixings designed for hollow walls.
Spring Toggles
Metal wings spring open behind the plasterboard.
| Size | Screw | Hole Size | Weight Capacity |
|---|---|---|---|
| Small | M4 | 10mm | 5-10kg |
| Medium | M5 | 13mm | 10-15kg |
| Large | M6 | 16mm | 15-25kg |
Pros: Strongest cavity fixing Cons: Need a bigger hole, toggle is lost if removed
Hollow Wall Anchors (Metal Rawlplugs)
Metal sleeves that expand behind the board when you tighten.
Weight capacity: 10-20kg per fixing Pros: Reusable, smaller hole than toggles Cons: Not as strong as spring toggles
Grip-It Fixings
Rotating wings that grip behind the board.
Weight capacity: 10-20kg Pros: Easy to use, small hole Cons: More expensive
Self-Drill Plasterboard Fixings
Plastic or metal fixings that screw directly into plasterboard.
Weight capacity: 5-10kg Pros: Quick, no pre-drilling Cons: Only for light items
What NOT to Use in Plasterboard
- Standard rawlplugs (they'll pull straight through)
- Long screws alone (nothing to grip)
- Nails (won't hold anything)
Stone Walls
Older Devon properties often have stone walls - either exposed or behind plaster.
Challenges:
- Stone can be hard to drill
- May hit voids behind stone
- Lime mortar is softer than modern mortar
Best approach:
- Drill slowly with masonry bit - let the drill do the work
- If you hit a void, try a different position
- Use longer fixings than you think - old walls are uneven
- For lime mortar: Consider resin anchors (inject resin, insert fixing)
Good fixings for stone:
- Brown rawlplugs for standard loads
- Shield anchors for heavy loads
- Resin anchors for crumbly mortar or heavy items
Concrete
Concrete is tough but holds fixings brilliantly.
Standard fixings: Use the same as brick, but you'll need:
- Hammer drill (SDS is even better)
- Masonry bits designed for concrete
Heavy loads in concrete:
Concrete screws (Thunderbolts, Turbos): Screw directly into concrete without plugs. Very strong.
Expansion bolts: For serious loads (structural brackets, etc.)
Quick Reference: What to Use Where
| Wall Type | Light Load (<5kg) | Medium (5-15kg) | Heavy (15kg+) |
|---|---|---|---|
| Brick | Red rawlplug | Brown rawlplug | Shield anchor |
| Block | Red rawlplug | Brown rawlplug | Shield anchor |
| Stone | Brown rawlplug | Brown + longer screw | Resin anchor |
| Plasterboard (stud) | Wood screw | Wood screw | Wood screw |
| Plasterboard (cavity) | Self-drill | Hollow wall anchor | Spring toggle |
| Concrete | Red rawlplug | Brown rawlplug | Concrete screw |
Common Mistakes
- Hole too big - The plug should be snug, not loose
- Wrong wall type - Test first, don't assume
- Plugs in mortar - Drill into bricks
- Standard plugs in plasterboard - They'll fail
- Underestimating weight - Books are heavy. Full shelves are heavier.
- Single fixing for heavy items - Spread the load
My Go-To Fixings
What I carry in the van and use most:
- General solid walls: Fischer UX (universal plugs - work in most things)
- Plasterboard heavy: Spring toggles or GripIts
- Plasterboard light: Self-drill plasterboard fixings
- Heavy on brick: 10mm shield anchors
- Concrete: Rawlplug R-LX concrete screws
Still not sure? I fix things to walls every single day. If you've got something to hang and you're not confident, give me a call. 01392 964094 or get a quote.
Sam Hembury
Sam is the founder of Hembury Contracting, providing professional handyman services across Exeter and Devon. With years of experience in property maintenance, he shares practical tips to help homeowners tackle common tasks.
