Dr Dulux: How to Paint onto New Plaster

Q. I’m painting new plaster and want to achieve a professional finish. How and when should I apply mist coat paint? What’s the best paint for new plaster?

A. If you’re wondering how to paint new plaster, you’re not alone. It’s a decorating dilemma that many homeowners face when a room has been replastered or a new wall built in. It’s important to note that painting new plaster is different to painting an ordinary wall. It requires more preparation – and patience! There are extra steps you need to take, including the application of a mist coat paint, before you can add a top coat of your chosen colour. The good news, you’ll find everything you need to know below.

How to paint new plaster? – 4 key steps to follow

1. Leave the plaster to dry

First things first, let your plaster dry properly! Plaster is extremely permeable, which means it’ll soak up any moisture quick. That’s why, allowing it to dry out will help you achieve a more even finish. There are different factors that influence how soon can you paint on new plaster, such as the type of material and weather. As a rule of thumb, plaster takes up to 4 weeks to dry completely. You can speed things up with a heater or by opening a window.

Top tip: If you don’t let the plaster dry and apply emulsion paint to wet plaster, it’s likely to crack and peel off.

2. Mix your mist coat paint

Painting new plaster that’s completely dry can also leave you with uneven brush strokes. So, the next course of action is to create your own mist coat paint. Mist coat paint is simply watered-down emulsion paint, which acts as your primer. All you need to do is get some white emulsion paint and thin it out with water – it’s that easy! Ten parts paint to one part water should work.

If you don't fancy watering down your paint you can also use Dulux Sealer for Plaster.

3. Apply your mist coat paint

Next, apply your mist coat paint to your newly plastered wall. Make sure you’ve prepped the area properly. Lay down dust sheets, cover furniture and get your brushes together. Learn more about prepping walls and the tools you need here. 

The mixture will soak into the wall and seal the plaster. It’s this extra layer of moisture that will help your top coat stick, so you can achieve a professional finish. If you spot any flaws in the wall, you can sand or fill them before adding your colour. Don’t forget to let your mist coat paint dry.

Top tip: Watch out for drips! Mist coat paint is really runny, so make sure you roll over drips before they dry.

4. Paint your walls with a top coat

The final step for painting new plaster is the most exciting – adding your top coat and that all important splash of colour. With all the prep work done, you can now paint your wall and decorate your room as you would normally.