Replastering gives a damaged or uneven wall a smooth, paintable finish. It takes patience and a feel for timing, since plaster sets as you work, but a small wall is a manageable project. This covers skimming a sound wall or patching an area back to flat.
What you'll need
- Plaster (finish/multi-finish)
- A clean bucket and mixing paddle
- Plastering trowel and hawk
- PVA bonding agent or diluted glue
- Sandpaper and a jointing knife
- Dust sheets
Step by step
- Prepare the wallScrape off loose or flaking material, brush away dust, and fill any deep holes first so you start from a sound, stable surface.
- Seal the surfaceApply a coat of diluted PVA bonding agent to control how fast the wall draws water out of the plaster, and start plastering while it is still tacky.
- Mix the plasterAdd plaster to clean water (not water to plaster), mixing to a smooth, lump-free consistency like thick custard, and only mix what you can use in about 20 minutes.
- Apply the first coatLoad the trowel from the hawk and spread a thin, even coat, working bottom to top and holding the trowel at a slight angle.
- Flatten and second coatOnce it firms slightly, apply a thin second coat to fill hollows, then work over it to level the surface.
- Trowel to a finishAs the plaster stiffens, make final passes with a clean, slightly wetted trowel to polish out lines, then let it dry fully before sanding lightly and painting.
Handy tips
- Keep your trowel and bucket clean, as dried bits drag lines through fresh plaster.
- Work in small areas if you are new to it, rather than trying to cover a whole wall in one go.
- Mist the surface with a little water if it starts drying faster than you can trowel it.
Heads up
- Plaster sets through a chemical reaction and can feel warm; never rinse leftover plaster down a drain, as it hardens and blocks pipes.
- Wear a dust mask when mixing and sanding, since fine plaster dust irritates the lungs and eyes.
FAQ
Can a beginner replaster a wall?
A small patch is doable with practice, but getting a large wall perfectly flat is genuinely difficult. Many people start with a small area or hire a plasterer for big jobs.
How long before I can paint?
New plaster usually needs to dry for several days to a couple of weeks depending on thickness and conditions, and should look uniformly pale before painting.
Do I need to seal fresh plaster before painting?
Yes. Fresh plaster is porous, so a thinned first coat of emulsion (a mist coat) is usually applied so later coats bond properly.