Painting a newly plastered wall requires more preparation than painting a normal wall. You can’t start painting new plaster directly and instead, have to take steps to seal the plaster so you can get the colourful finish you want.
What you’ll need
Emulsion for the mist coat
Water
Dust sheets
Decorator’s tape or masking tape
Topcoat paint
Paintbrush or roller
1. Let the plaster dry
The very first thing you need to do when painting new plaster is to let it dry.
A week should be long enough to let it completely dry out and for all damp patches to disappear, once the plaster is dry it should be light with no dark spots and a consistent colour and appearance throughout.
Your plaster will dry quicker with moving air, try not to use a heater as this will dry the plaster too quickly, which may lead to cracking.
If you try to apply paint to wet plaster this can cause adhesion problems.
Applying emulsion to wet plaster also means that it may not bond properly and you could find that it peels off your wall.
Painting on dried plaster can also cause the paint to dry very fast, leaving you with irregular brush strokes and an uneven finish, so to combat this, you need to apply a mist coat.
While the plaster is drying, put down dust sheets and use your tape to protect any fixtures and fittings, applying a mist coat can be very messy!
2. Mix a mist coat
A mist coat is made of watered-down emulsion paint and acts as a primer. The extra moisture gives the wall something to absorb so your topcoat should stick,
Alternatively, you can use a water-based primer which saves you the mess of making a mist coat.
To make a mist coat, mix three parts emulsion with one part water.
You should always check the paint tin for the manufacturer’s instructions as ratios can vary.
You don’t have to use exactly the same paint you’ve chosen for the final topcoat but you should use a similar colour for an even finish.
The mist coat will be completely mixed together when the water isn’t settling on the surface of the emulsion.
3. Apply the mist coat and let it dry
Once you’ve applied the mist cost, let this completely dry before apply the top coat.
4. Apply the topcoat
As soon as your mist coat has dried you can decorate normally.
There’s no need to sand down the wall as you’ve already done all the prep, so this bit is easy.
For the best results, you may need to apply more than one coat.