What ratio of paint-to-water on new plaster?

If you’ve recently had your house replastered, we bet you can’t wait to take to your walls with a paintbrush. But hold fire! Painting directly onto plaster can lead to your paint flaking off – far from the smooth finish you were after. Instead, you’ll need to prep your walls and ceiling with what’s

If you’ve recently had your house replastered, we bet you can’t wait to take to your walls with a paintbrush. But hold fire! Painting directly onto plaster can lead to your paint flaking off – far from the smooth finish you were after.

Instead, you’ll need to prep your walls and ceiling with what’s called a mist coat. This is essentially just a watered-down emulsion that soaks into the plaster to create a bond that will then allow your paint to stick properly.

What ratio of water-to-paint for new plaster?

You’ll find a few different ratios of water-to-paint floating around online when it comes to your mist coat. However, a common ratio is 3:1 – 3 parts paint to 1 part water.

Having said that, before you mix up your mist coat, make sure to read the information on the back of your paint tin. Many standard white emulsions will give you information on the tin about the best ratio for using them as a mist coat, so it’s worth heeding their advice.

If the paint you plan to use is thick, you might need to water it down more to achieve that runny consistency you need. For instance, 50:50 might be a better ratio for you. Ultimately, it’s safer to go a bit too thin than too thick.

How to water down paint for new plaster

Ready to take to your walls and ceiling with a mist coat? Follow these simple steps.

1. Wait for the plaster to dry. The longer you leave it to dry, the easier it will be to get an even finish.

2. Prep the plaster. Use sandpaper or a sander to ensure your plaster is completely smooth before beginning work.

3. Prep the area. Applying a mist coat can get messy. Make sure to lay down dust sheets, cover any furniture and protect your skirting boards with painter's tape.

4. Mix your mist coat. Use a matt emulsion to mix your mist coat. White is a cheap option that works with all colours, but you can use the same colour as your top coat if you prefer.

5. Apply your mist coat. Use a roller to finish the job quickly and achieve an even finish.

6. Leave it to dry. Give your mist coat at least 24 hours to dry. Once you’re sure there are no damp spots, you can start painting (usually, you’ll need two coats)!