Here at Painters World we regularly receive questions from homeowners regarding what the best paints to use are, especially when it comes to less common projects such as painting new plaster walls. That is why our experts have to put together this guide in order to answer any questions you may have, so you can get painting armed with all of the information you will need.

Painting Plaster

The first stage of any decorating project is understanding the surface you are trying to paint. By doing this, you are able to make informed decisions on what is the best course of action.

Plaster is a combination of sand and cement that is used to line walls ready for decorating. It helps to create a smooth finish that gives walls, ceilings and other structures a hard base that can be decorated.

Once a room is fully plastered, it can take up to four weeks for it to completely dry. For this reason, it is not as simple as painting the wall with any emulsion paint that is designed to be used on interior walls & ceilings. If you do not let the plaster dry before applying emulsion paint to the plaster, the paint will peel and flake off the wall as paint and moisture do not go well together.

Due to the fact that newly plastered walls cannot be painted using certain paints until they are completely dry, contract matt is the best paint to use. This is for a number of reasons, which include cost and moisture. Contract matt is a cheaper version of vinyl emulsion paints as they contain less polymer binders in their formulation. This makes them cheaper than other interior paints, meaning they are used by landlords and builders in newly plastered houses in order to have a painted surface. Furthermore, contract matt is permeable, which means it allows moisture to breathe through the paint film once applied. This means that it can be applied to plaster that has not been completely dried, allowing any moisture that has not dried to escape from the plaster.

This initial coating of contract matt acts as a primer for the wall, which can then be painted on with the paint of choice for your decorating project, once enough time has passed for any moisture to have escaped.

The contract matt is applied in what is known as a mist coat first, which is a diluted coat of paint that acts as a priming layer. The added moisture loosens that paint and allows the porous plaster to absorb some of this coat, thus preventing it from absorbing subsequent coats of paint. Primers can also be used, especially if it is a previously damaged plaster wall. Zinsser Gardz for example is a fantastic interior primer and sealer that creates a moisture resistant film that seals and binds down absorbent, chalky or crumbling surfaces, allowing them to be painted. To make a mist coat, simply dilute your contract matt with some water, anywhere from 10% to 30%.

There are a number of questions that you may be asking. Firstly, you may be wondering why you could not just wait for the plaster to dry completely before painting? This is an option if this suits you. One of the benefits of painting first with a contract matt is that often with new plaster in new build homes, it can take time for any settlement to occur. This can cause cracks in the wall that take time to show. As well as this, contract matt forms an excellent base coat for further topcoats of paint. If you apply an emulsion paint to completely dry plaster, it may not form the same quality of basecoat. By painting first with a contract matt, you allow this to occur before you apply your final decorative coat of paint, which is often much more expensive. You may also wonder whether you should use a PVA. We do not recommend this as the best way to paint new plaster as it can often lead to the paint film peeling, although this is suggested by some.

The Best Paint For Plaster

Finding the best paint to use for your project can be difficult, especially as paints often claim to do the same thing. The reality is, there are key differences in quality, coverage & durability that can make all a real difference.

When it comes to contract matt, our experts recommend using Dulux Trade Supermatt. This is a high-quality contract matt that is cited by many professional decorators as the best contract matt due to its fantastic opacity that helps to achieve a perfect finish in just two coats. There are cheaper contract matts on the market, however the quality of the paint and its coverage of up to 18m² per litre means it offers great value for money. Opting for a cheaper paint may save you money upfront, but with a poorer coverage will end up costing you more time & money.

Often when it comes to painting plaster, people look for a white shade. This is another reason our experts recommend Dulux Trade Supermatt as it has a fantastic finish even in white, which can often be a difficult colour to achieve a perfect finish in.

5L Dulux Trade Supermatt White

£31.25 exc. VAT

£37.50 inc. VAT

How To Paint New Plaster

Once you have decided what paint to use, the next stage is to follow our step-by-step guide to painting new plaster.

What You Will Need

1. Preparation

You must ensure that the surface is clean & sound before you apply any paint. If the plaster is previously damaged, you should ensure that you repair these before anything else. Use a good quality interior filler to repair any holes or cracks once you have cleared these of any debris or loose material.

Any dust should be cleaned off the plaster as this can gather under the paint film, causing it to completely blister off the wall. A damp cloth is best at removing this.

Finally, apply a masking tape to the edges of the surface you are painting and put down a dust sheet. This is important as your mist coat is thin, meaning it will run more than a standard coat of paint. This will save you time in the long-run as you will avoid any unnecessary cleaning.

2. Mist Coat

Once your plaster is clean & sound, it is time to apply a mist coat. Start by diluting your paint in a separate container to your paint as you do not want to dilute all the paint. Mix one part water to three parts paint. although you should follow the manufacturer’s instructions as each paint can vary.

Start with a paint brush, applying the mist coat around the edges of the wall first. Once this is done, using a 9" medium pile roller, apply the mist coat to the rest of the wall. Take your time as the thin paint will drip more than an ordinary paint.

Allow this to completely dry for 24 hours or as per the manufacturer's instructions before you apply for topcoat.

3. Top Coat

Apply your topcoat undiluted to the wall, once again starting with the edges using a paint brush and moving on to a roller for the bulk of the wall. For the best finish, ensure you get as close to the edge of the wall using your roller to prevent the framing effect. This is caused when a paint brush is used to paint around the edges of a wall and then a roller is used ton the rest. This difference in application causes a border to form around the wall, leaving an uneven finish.

By going back over the part you have used a paint brush on, you can ensure the finish is even throughout.

4. Decorative Coat

Once you have your fully painted wall, you may choose to paint over this with your final decorative coat of paint, if you want a particular paint colour. This can be done as far as 6 months down the line to give any settlement as much time as possible to unearth themselves, or alternatively can be done in around 4 weeks when the plaster has had a chance to completely dry out.

Frequently Asked Questions

Q. Why are patches appearing when painting new plaster?

A patchy finish can be down to a number of reasons. One explanation may be that you have applied the paint without a mist coat, which as we have explained helps to prime to plaster evenly in order to leave you with the best possible finish. It may also be down to the plaster being too thinly applied. Alternatively, if a PVA has been used, this may have been splashed which could cause patches on plaster.

Q. Why is paint peeling off a plaster wall?

Peeling paint can be a nightmare that can't be resolved with a one-fits-all approach. There are a wide range of reasons paint can peel, including the surface being damp, salt migrating through the plaster causing the paint to peel or the surface not being completely clean before painting. When it comes to plaster walls, peeling paint is most likely to be down to either the plaster not having a mist coat applied, a PVA has been used on the wall or there was dust or wallpaper paste on the wall when the paint was applied.

Q. Should you use PVA on plaster before painting?

PVA is a sealer that dries colourless and has a high bonding strength, which it is sometimes used to seal plaster before painting. It is however not recommended that you use PVA when painting plaster or plasterboard as there is no need. Not only can PVA cause the paint to peel, but it simply is not as effective as a mist coat for priming a plaster wall ready to be painted.

The reason paint often peels when PVA is used to seal a wall is that the paint sits on the film of the PVA instead of the wall. This impacts the ability for the paint to remain adhered to the surface, unlike a mist coat that will absorb into the plaster.

Q. What happens if you paint new plaster too early?

If you have applied paint to new plaster before it has dried enough to paint it will begin to peel off. This period is roughly 4 weeks but may be slightly longer depending on conditions. Unfortunately the only way to resolve this is to remove this paint using a paint scraper and starting the process again.

We hope this has answered any questions you may have had regarding how to paint new plaster and the best paint for plaster available in the UK. At Painters World we have a wide range of paint & decorating supplies available, so no matter the job, we've got everything you need to get painting. Shop our huge range of products today and get FREE next working day delivery on all orders over £50.

Secure payments, cards we accept: