Top Notch Walls logo org
Request Free Quote

How To Paint New Plaster

15 June 2023

Plaster walls are the ideal choice for many homeowners because of their beautifully smooth finish. Compared to plasterboard, however, adding the finishing paint touches to newly plastered walls takes some extra thought and consideration. But it will be worth it! Let's take a look at how to paint new plaster to get the perfect finish to take your room to the next level.

What You Will Need

Before you start painting, it is always a good idea to make sure that you have all of your supplies on hand. You will need:

  • tape
  • topcoat
  • paint
  • paintbrush
  • white paint
  • roller
  • dust sheets
  • masking tape
  • measuring jug
  • goggles
  • roller tray

Step 1 - Let The Plaster Walls Dry

When you are preparing to paint newly plastered walls, you should always take the time to let the plaster dry properly. This can be a long process because plaster is not a quick-drying material but it is worth the wait. The drying process for new plaster can be anywhere from a few days to four weeks but you are usually safe after one to two weeks.

What Is Plaster?

Many walls nowadays are created using plasterboard (or drywall) which is a ready-made board usually made of gypsum (the main material in wet plaster), and other materials such as paper, plastics, foam, and wool. Wet plaster can be applied to the plasterboard or can be created using undercoat plaster as a base.

Plaster is made of gypsum, lime, or cement combined with fine sand and water. It is applied wet by a skilled professional and once dry it creates a surface that can be both protective and decorative. It creates a smoother surface than plasterboard alone and can be used to create unusual shapes and even decorative elements. Don't also miss our article "How Much Does Lime Plastering Cost" - it offers valuable insights into this important topic.

Why Shouldn't I Paint Wet Plaster?

If you try to paint wet plaster, the moisture can prevent the emulsion in the paint from bonding with and adhering to the plaster surface properly. This will mean that the paint is likely to peel, bubble, and flake. It can also trap moisture which can lead to dampness issues.

How Will I Know When My Plaster Is Dry?

It can be difficult to tell whether new plaster walls are completely dry. The surface may feel dry to the touch but this doesn't mean that there isn't moisture underneath.

One of the easiest ways to tell whether plaster is dry is to keep an eye on the colour. As it starts to dry out, you will notice lighter colour patches appear on the surface. Once the entire wall is that lighter colour and there are no darker damp patches, then it is dry.

You can speed up the drying process of a newly plastered wall by opening a window and ensuring adequate ventilation. To learn more about how long does plastering take to dry, take a look at our post.

Step 2 - Prepare A Mist Coat

You can't paint directly onto newly plastered walls. Painting new plaster requires the use of a mist coat before going in with your paint colour. This step is important because painting new plaster directly won't leave you with the finish that you want.

New plaster is a very permeable material that will absorb liquid from the paint that you use. This will mean that you will end up with an uneven finish on your top coat, and often visible irregular brush strokes.

What Is A Mist Coat?

A mist coat is simply watered-down emulsion paint applied to newly plastered walls. The purpose of a mist coat is to create a seal over the new plaster so that when you do go in and paint it, it will no longer be permeable so you will have a nice even, and smooth finish.

How To Make Mist Coat Paint

Many people choose to use standard white emulsion paint for their mist coats. This is because white as a base coat will work well with whatever colour you have chosen for your wall. You don't have to use white, however. You could instead make a mist coat paint using the same paint colour that you will be using for the wall top coat.

Either way, you need to create watered-down emulsion paint, and doing this is as simple as it sounds. Take your paint and mix it with water at a ratio of three parts paint to one part water (use a measuring jug to measure your water out). Keep mixing it until the emulsion no longer sits on top of the water.

Some white emulsion paints will have the manufacturer's instructions on the paint tin for how to create a mist coat using them. If that's the case, then use the ratio that they suggest for their product.

Step 3 - Applying Your Mist Coat

Mixing emulsion paint to create a mist coat will create a runny solution. When you apply a mist coat to new plaster, the porous nature of it will absorb a lot of the moisture leaving the emulsion to create a seal on the surface. In other words, it works exactly like a primer.

This sealed surface will allow you to paint new plaster and leave a smooth finish and consistent colour over the entire wall because the emulsion will adhere properly to the wall surface.

To apply your mist coat, first spend some time prepping the area to reduce the mess as much as possible. Lay dust sheets over any furniture and carpet and cover your skirting boards, wall sockets, and other exposed surfaces with masking tape.

Next, make sure that the mist coat paint is fully mixed and that the plaster is completely dry, and that there are no damp patches visible.

Now you can apply the mist coat using a roller, a paintbrush, or both. A roller will create more mess but it is much quicker, whereas a paintbrush won't create as many drips or spray but it will take a lot longer. You could use a paintbrush for the edging and a roller to cover the main wall to make the process both quick and precise.

Mist coat paint is, by its nature, very runny. So there will always be a risk of drips snaking down the wall. As soon as you spot these, you should paint over them as quickly as possible. If the drips dry, then they will stop the finish from being smooth. You should apply the mist coat in smooth upward motions to reduce the drips as much as possible.

Some people apply more than one coat of mist coat paint but it often isn't needed. Just one coat is often enough to create the necessary seal. If you want to be doubly sure that your fresh plaster is completely covered, however, there is no reason why you shouldn't apply a second coat.

Leave the mist coat for around 24 hours before moving on to the next step of painting your newly plastered wall.

Step - Applying Your Paint

Once the mist coat is dry, then painting your completely fresh walls is exactly the same as painting previously decorated walls. You can apply paint in the same way as you would normally. There is no need to sand before you start because all the prep work has already been done.

Apply the paint using a roller in a V or motion to ensure even coverage of the wall. For the edges, use a paintbrush to make sure that you get into all of the nooks and crannies.

Once your first coat is dry, you should go in and apply your second coat or top coat. Two coats are often enough for your freshly plastered wall as there won't be any older paint colours underneath that could show through. But if you are unhappy with the paint finish after two coats, you could add a third.

Summary - How To Paint New Plaster

Painting a newly plastered wall requires extra steps compared to painting a previously decorated wall and the whole process can take a little longer. But as long as you remember the four main steps, you should end up with a beautiful paint finish to complement your new plaster.

1) Let the plaster dry properly making sure that all of the new plaster walls are a consistently lighter colour

2) Create some mist coat paint by mixing three parts emulsion with one part water

3) Apply your mist coat to the new plaster being careful to paint over drips

4) After the mist coat is dry, apply your desired paint colour in the same way as you would to a normal wall.

Hiring A Professional

Now you know how to paint new plaster, you can go ahead and get the process started. If you think you might be better off getting a professional in to help ensure that the finish is perfect, we are happy to help. Our team is very experienced with working with plaster, including painting new plaster, and will make sure that it looks exactly as you imagined.

While you're here, take a look at our post "How To Repair Plaster Walls" for more additional information.

FREE Plastering Quote
Top Notch Walls
FREE Plastering Quote
Free Call Us
0800 086 2915
Connect with Us
Facebook
© 2024 Copyright Top Notch Walls.
Plastering footer image