General · DIY guide
How to patch a wall after removing tiles
Pulling tiles off a plasterboard wall almost always tears the paper face away with them. The wall can be brought back, but it needs the right filler and patience with drying times — this is a job that is ruined by rushing.
Legal to DIY in Victoria
What you need
- Sealer or binder for torn plasterboard paper
- Base coat compound for the deep fills, topping compound for the finish
- 150mm and 250mm broad knives
- Sanding block with 120 and 180 grit
- Dust sheets and a dust mask
- Primer and topcoat
Step by step
Get the wall back to something sound
Scrape off all loose paper, adhesive lumps and blown plaster. Anything that is not firmly attached will show through the finish. Where the paper face is torn but the board is solid, seal it — unsealed torn paper bubbles when you apply wet compound over it.
Fill deep areas in layers
Use base coat compound for anything more than about 3mm deep, and build it in layers rather than one thick fill. Thick fills crack as they dry and shrink.
Feather wide, not thick
Each coat should be wider than the last, feathered well past the edge of the repair. A flat repair that is 500mm wide is invisible; a perfect one that is 150mm wide shows as a bump in raking light.
Let each coat dry fully
Compound that is touch dry is not dry. In a Melbourne winter allow a full day per coat. Sanding damp compound clogs the paper and leaves the surface soft.
Sand, then check with a light
Sand with the block, not just your hand. Then hold a torch flat against the wall and look along the surface — every defect you cannot see now will appear after painting.
Seal before topcoat
Fresh compound is far more absorbent than the surrounding paint. Prime the whole wall or the patches will flash through as dull spots in the finish.
Common mistakes
- Not sealing torn plasterboard paper before filling
- One thick fill instead of layers
- Sanding before it is properly dry
- Feathering too narrow
- Painting straight onto bare compound
When to stop and call someone
If the plasterboard behind the tiles is soft, crumbling or has been wet, patching is not the answer — the sheet needs replacing. In a bathroom, wet board also means water has been getting past the waterproofing.