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Plaster is easy to chip because the hard surface layer can crack or break away when a bit bites too aggressively. The safest approach is to support the surface, start with a small bit at low speed, and keep hammer mode off until you know what is behind the plaster. The right technique depends on whether the wall is plaster over wood lath or plasterboard, and whether you are drilling for a light picture or a load-bearing anchor.
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Identify the wall before drilling
Traditional plaster walls usually have a hard, brittle coating over narrow wooden laths. Plasterboard walls have a paper-faced gypsum core, sometimes with a thin skim coat of plaster. Tap the wall: lath-and-plaster often sounds uneven and solid, while plasterboard tends to sound hollow between studs. A stud finder can help, but thick or uneven plaster may confuse some models. Check for wires and pipes before drilling, especially near outlets, switches, radiators, and plumbing fixtures.
For a small hole, a short test with a thin masonry bit can reveal what you are hitting. Hard plaster may make fine pale dust; wood lath produces shavings; a hollow space behind the surface can mean you have passed through the plaster. Stop if you meet unexpected resistance or the bit suddenly drops forward.
Choose a drill and bit for the material
A standard cordless drill is usually the best choice for small holes in plaster. Use a sharp masonry bit for hard plaster, or a brad-point or wood bit once you reach timber lath. If the surface is plasterboard with only a thin skim, a sharp general-purpose bit may work. A small set of masonry drill bits is useful for brick or hard plaster, but you do not need a premium set for occasional picture hanging.
Leave hammer mode off at first. The hammering action can crack brittle plaster around the hole, particularly with larger bits or when the drill is held at an angle. A hammer drill is useful for masonry behind the plaster, but switch it on only after the bit has passed through the fragile surface and you are certain the material requires impact. An impact driver is not a substitute for a drill here: its pulsing torque can make a small bit wander or damage the hole.
| Wall material or task | Good starting tool | Main risk |
|---|---|---|
| Thin skim over plasterboard | Standard drill, sharp general-purpose bit | Tearing the paper face |
| Hard plaster over wood lath | Standard drill, small masonry bit | Chipping plaster or catching a lath |
| Brick or block behind plaster | Hammer drill with masonry bit, after the surface is cleared | Cracking plaster if hammer mode starts too early |
| Light fitting or picture | Bit matched to the anchor and wall | Using an anchor that cannot grip the wall |
Mark and protect the surface
Mark the hole with a pencil, not a sharp awl, which can break the surface before drilling. Put a small piece of low-tack painter’s tape over the mark and draw the center on the tape. The tape helps limit minor surface flaking, but it cannot prevent cracks caused by excessive pressure or hammer action.
Hold the drill square to the wall with both hands if the drill allows it. Set the clutch low enough that the drill does not wrench your wrist if the bit snags. If you are drilling near a fragile edge, such as a window opening or an existing crack, move the hole if possible; those areas are more likely to split.
Drill slowly and keep the hole controlled
Start with a 3 mm or 1/8-inch bit and run the drill at low speed with light pressure. Let the bit cut rather than forcing it. Once the surface is pierced, withdraw the bit occasionally to clear dust and check whether you have reached lath, a cavity, or masonry. If the final anchor requires a larger hole, step up gradually instead of forcing a large bit through the plaster in one pass.
Keep the drill aligned as you enlarge the hole. A tilted bit can lever against the plaster and lift a chip from the face. If the bit snags on wood lath, stop the drill, ease the bit back, and continue gently; hammer mode is not the answer. For masonry behind the plaster, use hammer action only after the plaster layer is safely cleared, and use the lowest effective speed and pressure.
Wear eye protection and clear dust with a vacuum or brush. Do not blow dust into the hole, where it can obscure the depth or irritate your eyes. Avoid enlarging a ragged hole by twisting a larger bit by hand; that can break away more of the surface.
Match the anchor to the wall and load
A plastic expansion plug can work in solid masonry, but it may spin or pull out of hollow plasterboard. For plasterboard without a stud, use an anchor designed for hollow walls and follow its stated weight rating. For heavier loads, fastening into a stud or masonry is more reliable than relying on the plaster skin. A hollow-wall anchor kit is a practical choice for shelves or other moderate loads, provided the wall type and load match the anchor instructions.
Do not assume an anchor rated for drywall is automatically suitable for old lath-and-plaster. The void behind the laths, the thickness of the plaster, and the condition of the wood all affect grip. If the fixture is heavy, pulls outward, or could injure someone if it falls, locate a stud or use a fastening system specified for the substrate.
Fix chips and avoid repeat damage
If a small chip forms, stop drilling and check whether the remaining surface is sound. For a minor flake around a hole, remove loose fragments and use a suitable filler before repainting. If the plaster has cracked well beyond the hole or sounds loose, do not hide the damage behind an oversized anchor; move the fixing point or repair the area first.
The cheaper standard drill and a basic sharp bit are fine for a few small holes. Spend more only when you need repeated masonry drilling, better dust control, or precise depth and clutch settings. The main protection against chipping is not a specialized drill: it is a small pilot hole, low speed, steady alignment, and keeping hammer action away from the fragile surface.