Fill a small hole in plasterboard

Find out what's behind the hole, prepare it properly, then fill and sand it flush so the wall is ready to paint.

FH-01Work out what wall you're dealing withKnock near the hole. A dull thud usually means solid brick or block, or dot-and-dab plasterboard on masonry. A hollow sound means plasterboard on studs. Run a magnet or stud detector across the wall: if it catches on screw heads in a line roughly 400mm or 600mm apart, you likely have timber studs; if the detector shows metal edges but a magnet doesn't grip, you likely have metal studs. Lath and plaster is usually in pre-1930s houses, feels slightly springy when you press near the hole, and the hole often shows thin wooden laths behind rather than flat board.

1 each · Small magnet or stud detector

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FH-02Protect the area and gather your kitLay a dust sheet under the hole and move anything nearby out of the way. Put on safety glasses and a dust mask, especially if you'll be sanding old plaster or lath and plaster, which can be dusty. Have your filler, filling knife, sandpaper and a torch ready before you start.

1 each · Dust sheet

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1 pack of 5 · Dust mask

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1 each · Safety glasses

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1 each · Torch

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FH-03Check what's inside the hole before you touch itShine a torch into the hole and look for any cable, pipe or wire poking through. Small holes from picture hooks or screws are usually safe, but never assume, especially near sockets, switches or where pipework might run. If you see anything that looks like a cable or a pipe, stop and don't fill over it. If in doubt, isolate the circuit at the consumer unit before doing anything else, and know where your stopcock is (usually under the kitchen sink) in case you later find a damp patch that suggests a pipe issue.

FH-04Clean and prepare the holeBrush away loose plaster, plasterboard dust or paint flakes from the hole and its edges. On plasterboard, gently undercut the edges of the hole with a filling knife so the opening is slightly wider inside than at the surface, which helps the filler grip. On lath and plaster, check the laths behind aren't crumbling; if they're solid, proceed, but don't push hard on them. On dot-and-dab plasterboard, press gently around the hole to check the board hasn't come loose from its adhesive dabs.

1 each · Filling knife

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1 each · Small paintbrush (for dust)

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FH-05Bridge holes bigger than about 10mmIf the hole is bigger than a small screw hole, filler alone will just fall through. On plasterboard over timber or metal studs, stick a self-adhesive scrim mesh patch over the hole, slightly larger than the gap, then fill over it. On lath and plaster, loosely scrunch a small ball of newspaper or masking tape into the gap behind the laths as a backing so filler doesn't drop straight through. On solid masonry or dot-and-dab, small holes usually don't need backing at all since the wall behind is solid.

1 roll · Self-adhesive scrim mesh tape

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FH-06Apply the first coat of fillerLoad a small amount of ready-mixed or mixed powder filler onto your filling knife and press it firmly into the hole, working it in from the edges to avoid trapping air. Leave it very slightly domed above the surface, since it will shrink a little as it dries. Leave to dry fully, following the time on the tub, usually a few hours for a small hole.

1 330ml tub · Ready-mixed multi-purpose filler

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FH-07Add a second coat if neededOnce dry, check the fill hasn't shrunk back below the surface. If it has, add a thin second coat, feathering the edges out onto the surrounding wall so there's no hard ridge. Leave to dry fully again before sanding.

FH-08Sand smooth and flushOnce fully dry, sand gently with fine sandpaper or a sanding sponge, working in circles, until the patch is flush with the surrounding wall and you can't feel a lip with your fingertips. Wipe away dust with a slightly damp cloth once you're done sanding.

1 pack · Fine sandpaper (120-180 grit)

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1 each · Cloth

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FH-09Prime and paint to matchNew filler is porous and will show through paint unless it's sealed first. Apply a mist coat (watered-down emulsion or a proper wall primer) over the patch, let it dry, then paint over with your matching wall colour, blending out to the nearest edges or corners so the repair doesn't stand out.

1 250ml · Matt emulsion or wall primer

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1 each · Small paint roller or brush

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FH-10Clean up and tidy awayFold the dust sheet inward to trap dust and shake it outside. Rinse your filling knife and any brushes, and wipe down the surrounding area. Let the paint cure fully, usually overnight, before touching the wall or hanging anything nearby.

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