August 25, 2023

How to Paint New Plaster

Key FAQ Points:

• Make sure plaster is completely dry, which typically takes around 4 weeks or even longer in cool or damp conditions.
• Prepare your plaster and put down protective floor covers.
• Use a mist coat to seal the super-porous bare plaster before painting.

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Without the right care and attention, paint on new plaster can become flaky or uneven. Read on as we briefly discuss drying times, preparation and mist coats when painting new plaster.

Make sure plaster is fully dry

First and foremost, ensure your plaster is completely dry. This is important as retained moisture may cause issues for your paint either straightaway or over time.

Generally, for most areas of new plaster, it can take around 4 weeks to dry out – but in damp or cool conditions this may take longer.

Preparing your new plaster

Once dry, check the surface of your new plaster. If there are any rough patches or debris adhering, knock this off with a quick sand. If there are any imperfections, you can fill and/or sand these before moving on.

Alternatively, if you have a super smooth, glass-like finish, it can be a good idea to lightly sand to whole area to maximise adhesion. Use a 120-grit sandpaper or finer for this and always remove sanding dust before starting to paint. Brush, hoover and/or wipe with a damp (not wet) cloth – then allow to dry.

It’s a good idea to put down protective floor covers in the area you’re painting – even more so with thinned paint as it can be more prone to dripping.

Now it’s time for the mist coat…

What is a mist coat and what is it for?

A mist coat is the application of a slightly thinned coat of paint in order to seal bare plaster – which is super porous. Generally, you only need a single mist coat.

The thinned paint partially absorbs into the plaster to seal it. This provides a good base for applying subsequent, un-thinned coats of your chosen colour.

Don’t be surprised if there is a patchy looking finish after your mist coat has dried. This is due to the very porous nature of bare plaster and should mean that subsequent coats are smooth.

Do you always need a mist coat?

Sometimes, it is tempting not to bother with a mist coat. And sometimes, you won’t have any problems as a result. However, by not applying one, you are running the risk of problems with adhesion.

If there are problems, it’s much more difficult to sort them out after the surface has been painted.

Paint that is not well adhered can crack, flake or even come off in strips! You may not be aware of the extent of the issues until you come to redecorate, even years later. As you apply new paint to badly adhered existing paint, it can pull away the surface.

How to apply a mist coat

After prepping the walls, thin your Frenchic paint with a maximum of 10% tap water and stir well. Apply as normal with a brush and/or roller – but do watch out for extra splashes and drips.

It’s best to leave your mist coat to dry for 24 hours due to the additional water it contains.

You should not count a mist coat as a full coat of paint. Check instructions on your tin, but for most paints, you will need 2 subsequent full coats.

Want to learn more? All of this is covered in our video on painting new plaster:

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Also in FAQs