What's inside
As an Amazon Associate I earn from qualifying purchases. This post may contain affiliate links at no extra cost to you.
What we cover
Choose the right plug and screw
A masonry plug, also called a wall plug, is a sleeve that expands inside a drilled hole as you drive in a screw. The plug grips the sides of the hole; the screw holds the item against the wall. It works only when the plug, screw, hole diameter, and wall material suit one another.
For a light picture or small bracket in sound brick, a basic nylon plug and matching screw are usually enough. For heavier loads, overhead fixing, or hollow and crumbly masonry, check the plug maker’s load guidance and use a fixing designed for that wall. Don’t assume a larger screw automatically makes a fixing stronger: an oversized screw can split the plug or prevent it expanding properly.
Read the plug packaging before drilling. It should state the required hole diameter and screw size or range. A common setup might use a 6 mm plug with a 6 mm drill bit and a screw around 4–5 mm in diameter, but sizes vary. If the package gives a screw length, follow it; otherwise, choose one long enough to pass through the item and engage most of the plug without bottoming out.
Check the wall and load
Brick, solid concrete, and hollow block need different approaches. A standard expansion plug is often suitable for sound solid masonry and modest loads. In hollow block, the plug may expand into a void without gripping enough material. In soft or damaged mortar, a hole may crumble and lose its hold. Use a fixing specified for the substrate rather than trying to compensate with a longer screw.
Before drilling, check for pipes and cables with a suitable detector and avoid drilling near electrical outlets, switches, and plumbing runs unless you know what is behind the wall. If you’re mounting something heavy, such as a wall cabinet or a television bracket, use the bracket maker’s fixing guidance and anchor into suitable masonry—not plaster, a loose brick edge, or a mortar joint unless the fixing is rated for it. Plaster is not a substitute for a solid anchoring surface.
Tools and drill settings
Use a masonry bit of the exact diameter specified for the plug. A bit that is too large leaves the plug loose; one that is too small can make insertion difficult and damage the plug. A masonry drill bit set is useful if you work with several plug sizes, but a single correctly sized bit is fine for one job.
A regular cordless drill with a masonry bit can handle many small holes in brick. A hammer drill makes drilling into hard brick or concrete faster, but the hammer action can damage soft or brittle masonry. Start without hammer action if you’re unsure, especially in softer brick. If progress is slow in solid masonry, switch to hammer mode and keep the drill straight. Choose a bit long enough to reach the required depth without forcing it.
For the screw, use a manual screwdriver or a cordless drill on a low clutch setting. An impact driver is usually unnecessary for small wall plugs and can drive the screw too hard, splitting the plug or stripping the hole. If you use one, work at low power and stop as soon as the item is secure.
Drill and fit the plug
Mark the fixing point and check it with a level if you’re installing more than one plug. Measure the plug and item thickness to estimate hole depth. The hole needs room for the plug and a little extra space for dust, but should not be much deeper than necessary. A piece of tape on the drill bit can act as a simple depth marker; don’t rely on it as a substitute for checking the plug length.
Hold the drill square to the wall. Drill steadily rather than leaning hard on the tool, which can bend the bit or widen the hole. Withdraw the bit occasionally to clear dust. After drilling, remove loose dust with a vacuum or a hand pump. Dust left in the hole can stop the plug seating fully and reduce its grip.
Push or tap the plug into the hole until its rim sits flush with the wall surface. If it won’t go in, don’t hammer it forcefully. Check that the hole is deep enough and clear of dust. If the hole is too small, carefully redrill with the specified bit. If it is already too wide or crumbling, a standard plug may not hold; choose a suitable repair or a different fixing rather than wedging in scraps.
Drive the screw
Position the item over the plug and start the screw by hand to make sure it enters straight. Drive it slowly, stopping when the item is snug against the wall. The screw should expand the plug, not crush it. If the screw spins without tightening, the plug may be turning, the hole may be oversized, or the substrate may be too weak. Stop and reassess; continuing to drive usually makes the damage worse.
If the screw binds before the item is secure, it may be too large, too long, or misaligned. Back it out and inspect the plug. Use the specified screw size rather than forcing a substitute. For a fixing that must carry a meaningful load, test by applying a cautious hand pull before loading it fully, and follow any load limits on the packaging.
Common options compared
| Fixing or tool | Best suited to | Main trade-off |
|---|---|---|
| Basic nylon plug and screw | Light to moderate loads in sound solid brick or concrete | Inexpensive and simple, but sensitive to the correct hole size and sound masonry |
| Longer or multi-purpose plug | Some mixed or less uniform masonry, when the maker specifies the substrate | More adaptable, but not automatically a safe choice for hollow block or heavy loads |
| Hammer drill with masonry bit | Hard brick or concrete where a standard drill struggles | Faster in hard material; hammering may damage soft brick or edges |
| Regular drill with masonry bit | Small holes in softer brick and occasional household jobs | Cheaper and gentler, but slower in hard masonry |
If you need plugs and screws for a basic household job, a nylon masonry plug and screw assortment can be good value. Check that the pack lists the drill-bit diameter and screw sizes for each plug, rather than relying on a generic “universal” label.
When to use a different fixing
Choose another fixing if the wall is hollow, the masonry is cracked or soft, or the load is heavy or safety-critical. A masonry anchor rated for the wall material may be more appropriate, but match its installation instructions to the actual substrate and load. If you can’t identify the wall or verify the fixing’s capacity, ask a qualified installer rather than trusting a plug that merely feels tight.