Summary: Learn how to paint new plaster, leave plaster to dry for correct amount of time and seal new plaster.
After a ceiling or wall has been plastered, it can take between 2 and 6 weeks to dry depending on circumstances. If the wall is in a centrally heated house, 4 weeks would be a safe time to start painting. However in a cold, damper environment, you shouldn’t paint until you are sure the plaster is completely dry. Painting plaster before it is completely dry will prevent the plaster from drying, and will cause mould growths which will be incredibly difficult to deal with.
There are however, Micro-porous paints on the market, which allow the surface beneath to dry. These are widely available in DIY stores. Micro-porous paints are generally a lot thinner than ordinary water or solvent based paints and in a lot of cases, once the wall is dry, it is recommended that you paint over them with emulsion. Please read the instructions on the container for information regarding thinning down and applying the first coat onto new plaster.
Sealing new plaster
A newly plastered wall is very porous and will absorb any ordinary paint that comes into direct contact with it. You will need to seal or prime the wall, failing to seal a newly plastered wall will result in the water based paint drying out and potentially peeling or flaking.
- First you will need to seal the surface, do this by mixing emulsion paint with water. You will want a 4:1 ratio, 4 parts emulsion to 1 part water. Make sure you stir thoroughly.
- Apply the sealer to the surface. You should hear the plaster sucking up the moisture. If you do not, then you can add a little more water. It is unlikely you will need to seal the wall more than once, but doing so will not cause any damage.
- Once dry the wall should be ready to paint with normal emulsion.
In kitchens and bathrooms, you should apply oil based paints on the walls and ceilings. This is due to the damp environment that will require a moisture repelling surface.
- For oil based paint, the surface of the plaster can be sealed using a solution of PVA adhesive.
- It is possible to purchase a plaster sealer if you are unsure of making your own mixes.
Painting new plaster video
Related projects
- Fixing plasterboard to a stud wall
- Painting new plaster
- Plaster interior walls
- Plasterboarding a ceiling
- Plastering over artex
- Repairing plaster walls
- Skimming plasterboard