How to patch a hole in plasterboard

Inspired by a helpful YouTube guide. This walk-through is based on the "How To Patch A Hole In Plasterboard" video from Tommy's Trade Secrets, a well-established UK trade tutorial channel. What it does well is show the different methods side by side — so you can pick the right one for the size of damage you have, rather than guessing.

1. Assess the hole and choose your repair method

Stand back and look honestly at the damage. Small holes — under about 20mm across — can be filled directly. Medium holes up to roughly 100mm need a mesh patch to give the filler something to grip. Anything bigger than that needs a timber backing piece or a dedicated plasterboard repair kit.

Also check what caused the hole. If a door handle went through the board, worth considering a wall stop or rubber door stop so it cannot happen again once the repair is done.

2. Small holes: fill directly with filler

For dents and small holes up to 20mm or so, dampen the area slightly with a wet brush first — dry plasterboard soaks up moisture from the filler too fast, which can cause shrinkage and cracking. Apply ready-mixed filler with a flexible knife, slightly overfilling the hole.

Once dry, sand flush and repeat if there is any shrinkage. Fine surface filler or finishing compound gives a smoother result than standard all-purpose filler for the final skim coat. A light sand with 120-grit, then 180-grit, and you are ready to paint.

3. Medium holes: use a self-adhesive mesh patch

Mesh patches — available from most DIY and trade suppliers — are aluminium-faced patches that stick over the hole and give filler a surface to bond to. Clean around the hole first and trim away any jagged edges of board that might push through the mesh.

Apply the mesh, then skim filler over it in thin layers, feathering it out well beyond the edges of the patch so the repair blends into the surrounding wall. Thin coats are the key here. Thick filler shrinks and cracks; two or three thin coats, each fully dry, produce a much flatter result.

4. Larger holes: fit a timber backing piece

For holes over about 100mm, the cleanest method is to cut the damage into a neat rectangle using a padsaw or multi-tool, then fit a length of timber behind the opening as a backing piece. The timber should be slightly wider than the opening so it can be screwed from the front through the existing board on either side.

Cut a patch of new plasterboard to fit the opening, screw it to the timber backing, and then skim over the whole repair with jointing compound or a thin finish plaster. The result is solid and barely visible once painted. To be fair, this method takes longer, but for holes bigger than a fist it is the right approach.

5. Apply filler in thin layers

Whether you are skimming over a mesh patch or topping out a board repair, the same rule applies: thin coats only. Apply, let it dry fully, and sand before applying the next. Trying to fill a deep repair in one thick coat leads to cracking as the outer surface dries before the material underneath.

Ready-mixed filler is fine for most jobs. For repairs that need a very smooth finish, finishing plaster or a dedicated skim compound gives a finer result and sands more easily. A flexible 150mm or 200mm filling knife keeps the filler flat and reduces sanding time.

6. Sand smooth once fully dry

Start with 80 or 100-grit to knock back any high spots, then move to 150-grit and finally 180 or 240-grit for a smooth finish. Wipe the dust away with a damp cloth and leave to dry before painting.

Hold a torch at a low angle against the wall and look across the surface. Any remaining bumps will show clearly — much better to catch them now than after painting. The wall does not need to be perfect, just flat enough that paint does not highlight the repair.

7. Spot-prime before painting

Bare filler and plasterboard are both very absorbent. If you paint straight onto them with emulsion, the repair absorbs the colour differently to the surrounding wall and the patch shows through as a dull spot even after two or three coats. A spot coat of diluted emulsion or a proprietary primer seals the repair and means the topcoat goes on evenly.

Allow the primer to dry, then paint the area to match the rest of the wall. You may need to repaint the whole wall to get a perfect colour match on painted surfaces, particularly if the existing paint has faded or changed shade over time.

When to call a handyman

Call Richard if the damage is extensive, if the boards are damp or damaged by water, or if the repair needs a skim plaster finish that blends invisibly into the surrounding wall. The Sandwich Handyman can help with plasterboard repairs, filling, and painting in Sandwich and across East Kent.