Painting new plaster is often a key step to transforming the walls and ceilings in your home. Creating smooth, freshly painted walls and ceilings is an easy and cost-effective way of giving your home a makeover. However, there is a lot of conflicting advice online on what the best methods and practices for painting new plaster are.
There are so many things that you need to consider before painting new plaster. Should you seal your fresh plaster with PVA? What type of paint should you use on new plaster? Should you treat skimmed plaster differently to a surface that has been fully plastered? In this article, we will answer all of those questions and more. We will take you through every aspect of plastering and painting so that you can confidently redecorate your home.
How Long Does It Take for the Plaster to Set?
The length of time it takes for the plaster to set will entirely depend on the type of plaster that you use. Below, we have a list of common types of plaster, what you can use them for, and how long you will have to wait for it to set. Once the plaster has set, you should still make sure that you wait for it to totally dry before attempting to paint it.
|Browning||Basecoat for walls, brickwork, blockwork, breeze block, plasterboard ||2 hours|
|Bonding||Basecoat for walls, brickwork, blockwork, breeze block||2 hours|
|Multi-Finish||Topcoat for browning and bonding||1-1.5 hours|
|Board Finish||Topcoat for plasterboard||1-1.5 hours|
|One Coat||Small DIY jobs||2-2.5 hours|
How Long Should You Wait Before Painting New Plaster?
One of the most common questions that arise about plastering and painting is how long you have to wait before painting new plaster. Above all, recently plastered walls should be left to dry thoroughly before any painting begins. The time you should wait before painting new plaster depends on several factors. Firstly, have you used plasterboard, or backing plaster?
Plasterboard takes on average 2-3 days to dry when plastered, whereas backing plaster takes 4-6 days.
No matter what material you have used, it is advisable to wait at least a week
before painting new plaster. Sometimes it may even take up to a month for the fresh plaster to be completely dry. You should ensure that there are no dark patches on your freshly plastered surface before you attempt to paint it. Uniform light colour is a key sign that your plaster has dried thoroughly. We have included images below of to show you what the drying process looks like so that you will know what to look out for. Even if your plaster is only showing a couple of small, dark patches, you should only start painting when they disappear.
But… Isn’t a Week a Long Time to Wait?
A week may seem like a long time to wait, and it’s understandable that you may get frustrated with the delay. But, if you want to achieve the perfect finish, the wait time will be worth it. The time fresh plaster takes to completely dry will differ in every case. Factors such as the time of year, central heating, and how many layers of plaster there are will affect the time that it takes.
You should make sure that the room that has been plastered is well ventilated. Opening windows and doors to let natural ventilation flow through the room will gently dry your new plaster. This will also help you to avoid the risks associated with rapidly drying new plaster, such as cracking.
What Is a Mist Coat?
When you are painting new plaster, preparing and applying a mist coat is an essential step that you cannot skip. Applying a mist coat is beneficial for a number of reasons. Firstly, if you start painting on new plaster with unthinned emulsion, you will find that it dries too quickly. A normal emulsion will not bond properly with the surface that you have plastered but a diluted mist coat will.
If your paint dries too quickly, you are likely to find that it starts to peel and that it leaves your surface with an unprofessional finish. Additionally, your paint will not last as long without a mist coat, and you may need to repaint sooner. So, to save yourself time and money in the long run, a mist coat is essential.
There are specific paints on the market that you can purchase that allow you to paint directly onto new plaster. If you are short on time and you need to finish your project quickly, new plaster emulsion may be useful. The key benefit of new plaster emulsion is that it is significantly thinner than standard paint. This means that you do not need to wait for your plaster to completely dry before starting to paint with it. If you are looking to paint your new plaster immediately, why not try the Wickes Trade Paint For New Plaster Emulsion or the Dulux Trade Supermatt? These preprepared paints are a good choice if you are new to painting and decorating and if you want to finish the job quickly.
How Do I Create a Mist Coat?
If you are in a hurry, new plaster paint is a good time saver. However, be aware that these paints can be expensive compared to a standard emulsion. It is also advisable to paint over new plaster emulsion with a standard emulsion after it has totally dried. This is because new plaster emulsion is significantly thinner than standard paint, so it may not provide a high-quality finish if it is used alone. Using thicker emulsion as a final step will ensure that your surfaces look professional. So, you may find that buying extra emulsion to act as a mist coat is an unnecessary extra step.
Instead of buying an expensive new plaster emulsion, you can easily create your own mist coat. It couldn’t be simpler to make. All you need is standard emulsion and water. Any light coloured emulsion will work, as these colours will not show through your top coats of paint. The ratio should roughly be 4 parts water to 6 parts paint. Depending on the emulsion you are using, you may need to alter this ratio in order to achieve a more diluted paint. For more information, you can check out our mist coat
Diluting Paint for a Mist Coat
Diluting the paint is essential, as it allows the mist coat to sink into the wall, which seals the surface. An undiluted standard emulsion will draw the moisture out and dry too quickly, creating cracks, and causing the paint to sit on top of the new plaster. Also, make sure that the standard emulsion you are using in your mist coat is non-vinyl. A vinyl emulsion will form a skin on the surface of your plaster. It will also be prone to peeling as this type of paint will not be able to sink into the surface.
Applying a mist coat will sufficiently seal your new plaster after it has dried. Many professional painters do not recommend using PVA glue to seal your plaster, as it can cause issues later on. The paint that you then apply afterwards is likely to sit on top of the PVA if you use this method. This means that it will fail to deeply penetrate your surface and subsequently the paint will not last very long. Paint quickly starts to peel off and chip away if plaster has been treated with PVA prior to application.
Can I Speed up the Drying Time?
Some people recommend using a dehumidifier in order to speed up the process of drying your new plaster. However, you should be cautious when using this technique. If you rapidly remove the moisture from your recently plastered surface, you may find that it starts to develop cracks and other imperfections. The easiest way of ensuring that you keep your plaster perfect is to allow it to dry naturally. It may be frustrating to have to wait before you can add paint to your surface, however, dealing with the cracks will be more annoying in the long term!
Should I Sand down the Surface Before Painting?
If you have hired a professional to plaster your walls or ceiling, it is unlikely that you will need to sand down the surface before painting. Usually, if a plasterer has completed the work to a high standard, you will be able to apply a mist coat immediately after the plaster has fully dried. However, sometimes a light sanding might be necessary if you can see some minor imperfections in the plastering, or if you plastered the surface yourself.
It’s a good idea to be very cautious when you are sanding a freshly plastered wall or ceiling. Opting for light to medium grade sandpaper should prevent you from overly sanding down the surface. If you use sandpaper that is too coarse, you may find that you end up scratching your walls. Overly sanding your plastered surface may also make your surface too polished and prevent the paint from properly sticking. When choosing the sandpaper that you are going to use on your plaster, choose 120 grit or higher
. The higher the number, the finer the sandpaper will be, which is better for gently smoothing out surfaces than coarser sandpaper.
Is There a Difference Between Internal and External Walls When You’re Painting New Plaster?
The short answer is yes, there are several things you must do differently when you are painting new plaster on an external wall. Firstly, you should prepare your external walls with a scrapper. This will allow you to remove any remaining bumps to the surface. For smaller loose particles and dust, a wire brush will work well.
Selecting paint that is suitable for external use is essential. Choose masonry paint
that can be used on a variety of surfaces. You can use masonry paint on plaster without diluting it. So, you do not need to use a mist coat when you are painting exterior surfaces. If you are painting new plaster on an exterior surface, you will typically need to use two coats of paint.
What Is the Difference Between Skimming and Plastering?
Professional plasterers can use a variety of plastering techniques for different purposes. Sometimes a surface will not need to be fully plastered if it has already been plastered previously. Skimming is a good option if your plasterwork needs an upgrade, but it does not need to be totally replaced. It is a technique that is primarily used to smooth a surface that has been plastered before.
Quickly skimming a plastered surface before painting is a useful technique if you want to make sure that the paint will be applied smoothly and look even. However, you cannot use the skimming technique to level plaster. To level a wall, you will need to use a backing plaster first, before you skim the surface. A freshly skimmed surface should take less time to totally dry. On average, it should take around three days for the skimmed surface to dry and be ready for painting.
Is It Worth Hiring a Professional to Paint Fresh Plaster?
When you are giving your home a makeover, it’s important to get it right the first time. This will save you time and money in the long run. Although DIY is great for small projects, hiring a professional painter is a better option for larger jobs. Hiring a painter and decorator guarantees that you will receive professional results. If you hire a professional painter, you will find that the paint lasts a lot longer.
We hope that you enjoyed our guide on painting new plaster. You can also check out our guide on the average cost to paint a room
as well as the national average cost for painting in the UK
, for more information on painting and decorating. If you are looking for a local professional, see our list of interior painters
and request a painter and decorator or a plasterer near you. You will then receive bids from local professionals who are ready to help you. You can then select the one that is right for you, and enjoy your home makeover!