How do I repair a hole in plasterboard?

The size of the hole decides the method entirely. Filler has no strength across a void, so anything bigger than a few centimetres needs something behind it to hold the filler — either mesh or a real piece of board.

What you'll need

• Filler and a filling knife
• Self-adhesive mesh patch
• Sandpaper (120 and 180 grit)
• Offcut of plasterboard and timber batten (optional)
• Padsaw or utility knife (optional)

Step by step

1. Measure the hole and pick the method: under 25mm fill directly, 25–100mm use a mesh patch, over 100mm cut in new board.Trying to bridge a large hole with filler alone always cracks out within months.
2. Cut away any loose or crumbling board back to sound material.A clean square opening is far easier to patch than a ragged one.
3. For a mesh patch, stick it centrally over the hole and press it down firmly.It needs to bond to sound board all round, so cut it larger than the hole.
4. Apply the first coat of filler over the mesh, pressing it through the weave.Thin. You are bedding the mesh, not filling the hole in one go.
5. For a cut-in patch, cut a square opening, screw a timber batten behind at each side, then screw in a board offcut.The battens give the new board something to fix to. Screws slightly below the surface.
6. Tape the joints with scrim tape and fill in two or three thin coats, feathering wider each time.Each coat wider than the last is what makes the repair invisible. One thick coat leaves a visible bulge.
7. Let each coat dry fully, then sand flush with a flat block.Flat block, light pressure. A fingertip digs a dish around the repair.
8. Spot-prime the repair before painting.Filler is more absorbent than the surrounding wall and will flash as a dull patch through the topcoat.

Tips

• Run your hand over the dry repair with your eyes shut. You will feel a ridge you cannot see, and so will the paint.
• For a hole made by a door handle, fit a door stop at the same time or you will be repairing it again.
• Check for cables and pipes before cutting into any wall, even to enlarge an existing hole.

Common mistakes

• Filling a large hole without backing — Filler has no strength across a void — it cracks and drops out within weeks.
• One thick coat instead of several thin ones — Thick filler shrinks and leaves a visible bulge or dip.
• Skipping the spot prime — The porous repair absorbs paint differently and shows as a matt patch.

Questions people ask