Repairs & Maintenance · 8 min read · Intermediate

How to Patch Small Holes & Damaged Plaster

Repair small local plaster defects while recognising when cracks, damp or loose background mean the problem needs diagnosis rather than filler.

Key points & steps

Inspect the defect before filling it. Active damp, repeatedly opening cracks, hollow or loose plaster, major movement and large damaged areas should be investigated rather than simply covered.
Remove loose or crumbling material back to a sound edge without unnecessarily enlarging the repair.
Brush or vacuum dust from the repair and prepare the background using the filler/plaster manufacturer’s instructions. Very absorbent backgrounds may need controlled dampening or a specified primer/bonding treatment.
For deeper holes, use a repair product suitable for the depth and build in layers if the manufacturer requires it rather than trying to bridge a deep void with a thin finishing filler.
Apply the final layer slightly proud or level depending on the repair material, feathering the edges onto sound surrounding plaster.
Allow the product to dry/cure fully before sanding. Sand only enough to blend the repair without hollowing the centre or damaging surrounding paint.
Prime or mist/prepare the repaired area as required by the paint system before applying finish coats.
If the defect returns, investigate movement, moisture or poor adhesion instead of adding another cosmetic layer.

Do not fill over damp or powdery material and expect the repair to last.
Hairline cosmetic cracks and structural/movement cracks are not the same problem.
Deep repairs often work better with a suitable base repair followed by a finer finishing layer.