When thinking of painting over plaster on a new wall or ceiling it’s important you do all the necessary preparation compared to a wall that’s been previously painted. You have to take steps to seal the plaster so you can get the perfect finish with your colourful topcoat.
What you need to paint new plaster:
- Dust sheets
- Decorator’s tape or masking tape
- 120 grit sand paper
- Emulsion for the mist coat
- Vessel to mix the emulsion and water together
- Paintbrush and roller, tray
- Colourful topcoat emulsion
Let the plaster completely dry
Make sure the plaster is completely dry before doing anything. How do you know when it’s dry? It should have a light uniformed background. If there are any darker shades it means it’s still wet in places. Depending on the depth and number of coats of plaster, as well as the temperature in the room it can take weeks for the plaster to dry. Please be patient and allow time for it fully dry out. Don’t be tempted to speed this process up with heaters or dehumidifiers, this could crack and damage the plaster.
Use dust sheets to protect floors and large furniture, then tape any fixtures and fittings that you want protected from the paint. Applying a mist coat can be messy as the paint is thinner than usual.
Lightly sand the plaster with 120 grit sandpaper to remove any small imperfections and to key the surface. If the plaster is too shiny the paint won’t adhere.
Seal the plaster with a basecoat
This is usually called a ‘mist coat’ which is a water based emulsion. You can make your mist coat by watering down a standard emulsion, 4 parts water to 6 parts paint. You don’t have to use the exact same paint you’ve chosen for the final topcoat but you should use a similar colour for an even finish.
Why can’t I use normal emulsion? Standard emulsion has a higher vinyl content and means it’s too thick to paint fresh plaster effectively, it won’t adhere and can cause peeling. You must always water down your first coat to create the best adhesion.
You will know when the mist coat is completely mixed together when the water isn’t settling on the surface of the emulsion.
Using a roller will cover your plaster quickly, although it can get quite messy as it will spatter the paint easily. Work in a smooth upwards motion until the entire wall is covered. As the mist coat is very runny, look out for drips or streaks and paint over them quickly to get an even finish once dried.
Apply your chosen colourful topcoat
Allow 24hrs for the mist coat to dry. If there are any minor cracks showing fill with a multi use filler, let it dry and then sand it back. You are then ready to paint! We suggest at least three coats of your chosen emulsion applied sparingly with a roller.