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What Can You Plaster Over

This guide aims to provide clarity on whether it is possible to plaster directly over various finishes within your home.

While some finishes may allow for direct plastering, others may not, and it is important to understand these differences before attempting any costly and potentially damaging mistakes.

In case you’re wondering what can you plaster over, you’ll have an answer addressing various finishes. Let’s look at each in turn.

What can you plaster over?

Can You Plaster Over Wallpaper?

Plastering over wallpaper is possible, but it is not recommended by professionals. The wallpaper’s dry surface can make it difficult for the plaster to bond properly, resulting in an uneven and unprofessional finish. It is always best to remove the wallpaper before plastering for a smooth and long-lasting finish.

However, if removing the wallpaper is not possible, there are some steps that can be taken to prepare the surface, such as cleaning and sanding the wallpaper to provide a better surface for the plaster to bond to. Overall, it is best to consult with a professional before attempting to plaster over wallpaper.

Can You Plaster Over Artex?

Artex is a textured surface that was commonly used for ceiling decoration and wall texturing in the 1970s.

While it may have been fashionable back then, it is now considered outdated and difficult to repair or clean.

Plastering over artex surfaces is possible, but it requires careful consideration of the texture height and the appropriate steps to follow.

Is Artex Dangerous?

It is important to note that until 2000, artex materials contained asbestos, which is a very dangerous substance. Asbestos is generally considered safe unless it is disturbed.

Once it is disturbed, particles of dust and debris can be inhaled, which is toxic and can damage the lungs and cause serious diseases. Although artex contains low levels of asbestos, the dust and fragments when removing it could cause serious health concerns.

If you want to remove artex, it is highly advised to have it done by a professional. It is also important to check whether the decoration was done before or after 2000.

When plastering over artex, the texture height must be considered. If the height of the designs protrudes from the surface quite a lot, it may be best to remove the bulk of them using a metal tool such as a floor scraper or a wallpaper scraper. This will make the surface smoother and easier to work with.

After removing the high points of texture, the following steps should be taken:

  • Apply A Base Coat: Applying a base coat to the surface is an extremely important step. The go-to base coat is a PVA emulsion. It is important to apply this emulsion to the entirety of the surface, and a top tip when doing this is to add either food colouring or a handful of plaster to the mixture. This will give the PVA a slight tint, which will allow you to see the areas you have covered.
  • Apply A Second Coat: Depending on the porosity of the surface, you may need to add a second coat of PVA. You want your PVA to be tacky when applying the first layer of plaster, as this will ensure there is an adhesive bond between the base coat and plastering.Quite often, applying a second coat of PVA is the best course of action.
  • Skim Ceiling With Plaster: Once the PVA has dried, and is tacky, apply the first layer of plaster. Wait around 7-10 minutes for this layer to firm up, and then use a trowel to clean up any edges and flatten down the plaster.This will ensure that there will be no uneven areas or trowel marks when applying the next layer. At this point, it doesn’t matter if the plaster takes up the shape of the artex design, as you will be adding more layers on top of it.
  • Add A Second Coat Of Plaster: Wait about 15-30 minutes for the previous layer of plaster to dry. This is the best period of time to apply a second coat, as you want the previous coat to still be damp.Apply your second coat, which should be thicker than the first layer as the aim is to cover the high points of the artex completely. Wait for this layer to firm for 7-10 minutes and then repeat the step of cleaning up edges and flattening the plaster.
  • Apply A Third Layer If Necessary: If you can still see the texture of the artex, apply a third layer of plaster. Wait 7-10 minutes and then repeat the cleaning and flattening step.

It is important to apply a new layer of plaster only when the previous layer is damp. If you apply the new layer too soon and the surface is too wet, it will disrupt the previous layer. If you apply it too late and the surface is dry, you may face cracking and flaking in the future. This is due to the previous layer of plaster sucking too much moisture out of the next layer, causing it to dry too quickly.

If you don’t have time to finish plastering your wall the same day, apply a thin layer of water to the dry plaster before applying the next coat.

Can You Plaster Over Paint?

Plastering over a painted surface can be a convenient way to refresh a room or repair a damaged wall. However, before doing so, there are a few factors that need to be considered to ensure a successful outcome.

Condition of the Paint

The condition of the paint is the most important factor to consider when plastering over a painted surface. If the paint is in good condition and not in need of any maintenance, it is perfectly fine to skim over it with plaster.

However, if the paint is old, flaking, or damaged, it is recommended to remove it before plastering. Applying plaster over a damaged painted wall can cause the plaster to detach from the wall in the future or crack and flake.

To remove the paint, wash the walls with a sponge, soap, and water to remove any debris, dust, and grease. Use a metal scraper to scrape off as much of the loose paint as possible. If patches of the paint are proving to be stubborn, a sanding block can be used to sand away at the paint before scraping.

If all else fails, a chemical paint stripper can be used to lift the paint, making it easier to scrape away. After removing the paint, the wall should be cleaned again to remove any leftover debris before plastering.

Preparation

Before plastering over a painted surface, the surface must be cleaned thoroughly. Use a sponge and soapy water to clean dirt, debris, and grease from the wall before moving on to the next steps.

The next step is to apply a layer of PVA emulsion to the surface, as this will create an adhesive bond between the surface and the plaster. Skipping this step can cause the plaster to crack and flake.

After applying the base coat, apply a first layer of plaster, wait 7-10 minutes for it to firm, and then flatten any trowel marks and bumps. After about 15-30 minutes from applying the first layer, apply the second layer of plaster, and repeat the flattening step 7-10 minutes after the second layer has been applied.

Depending on the condition of the wall underneath, a third layer may be necessary, but this isn’t always the case.

Wait

Before applying any paint or wallpaper to the freshly plastered wall, it is important to wait for it to fully dry. Plastering can take up to 6 weeks to fully dry. It is recommended to wait at least a week before applying anything to the wall.

Repairing Holes and Cracks

If the wall has any cracks or damages, they will need to be repaired before plastering. Smaller holes and cracks in a wall can be filled using a sealant such as Caulk.

Larger holes and cracks will have to be filled with plaster and mesh, which may be a job for a professional.

In conclusion, plastering over a painted surface is possible, but it is important to consider the condition of the paint and prepare the surface properly. If the paint is old or damaged, it is recommended to remove it before plastering. By following the steps outlined above, you can ensure a successful outcome and achieve a smooth, refreshed surface.

Can You Plaster Over Plasterboard?

Plasterboard, also known as drywall, is a popular material used in modern construction. It is made up of gypsum plaster that is sandwiched between two layers of paper and dried. When it comes to plastering over plasterboard, there are a few things to keep in mind.

Skimming is the most common technique used to achieve a smooth finish on plasterboard. It involves applying a thin layer of plaster over the surface, rather than multiple thicker coats. This technique is quicker and easier than traditional plastering methods, as the boards are premade and cut to the dimensions of the building, and then secured to the framing.

Before plastering over plasterboard, it is important to consider scrimming the joints. Scrimming involves reinforcing the corners of the plasterboard with scrim tape, which strengthens them and covers any lines and holes.

The plaster will set into the mesh of the tape, preventing cracking and lines from appearing in the future.

When plastering a drywall, it is not always necessary to apply a layer of PVA as a base coat. Instead, dampening the surface slightly with water is sufficient. However, it is important not to apply too much water as it can damage the surface.

If the plasterboard is quite old, it may benefit from a layer of PVA first. It is important to determine how long the plasterboard has been there for before beginning the plastering process.

When skimming plasterboard, two thin coats of plaster should be sufficient. It is important to wait 7-10 minutes for the plaster to firm up before smoothing out any imperfections and applying the next coat. The next coat should be applied 15-30 minutes after the previous coat.

In summary, plastering over plasterboard requires a different technique than traditional plastering methods. Skimming is the most common technique used to achieve a smooth finish. Before beginning the plastering process, it is important to consider scrimming the joints and determining whether a layer of PVA is necessary. Two thin coats of plaster should be sufficient for skimming plasterboard.

Can You Plaster Over Tiles?

While it is possible to plaster over tiles, it is not recommended by professionals due to several reasons. One of the main reasons is that tiles are not an ideal surface for bonding plaster to. When plastering a surface, the surface needs to bond to the PVA base coat.

However, due to most tiles being extremely slippery and unable to absorb moisture, the PVA base coat layer will not bond to the wall, resulting in a weak surface that can cause the plaster to flake and detach easily.

Another issue with plastering over tiled surfaces is that it makes it difficult to drill into the surface. Tiled surfaces are typically found in kitchens and bathrooms and require appliances such as sinks, lavatories, and kitchen counters to be attached to a strong surface. Drilling into plaster attached to tiles can cause cracks and damages.

If you are considering plastering over tiles, it is essential to keep in mind that removing tiles is a relatively simple task. Removing tiles with a chisel and hammer is a small price to pay to avoid a whole host of problems in the future.

However, if you are unable to remove the tiles, you will need to use the correct materials. Blue Grit is the best bonding agent to use on tiles instead of PVA. Unlike regular PVA, Blue Grit creates a bond between itself and the wall, which is essential when plastering.

If you do not have time to remove the tiles, apply a layer of Blue Grit bonder to them first as a primer, let it dry thoroughly for around 24 hours before applying your plaster. Unlike regular PVA, Blue Grit only needs one coat.

In summary, while it is possible to plaster over tiles, it is not recommended by professionals due to the difficulties in bonding plaster to the surface and the limitations it creates when drilling into the surface. Removing tiles is a relatively simple task and will help avoid future problems. However, if you cannot remove the tiles, using Blue Grit as a bonding agent is the best option to ensure a strong and durable surface.

Can You Plaster Over Brick?

Plastering over brick can be a challenging task, especially if the brick is old and deteriorating. If the wall is crumbling, it is not recommended to apply plaster to it, as it will not stick well to the surface, and there is a risk of major damage to the plaster in the future. If the wall is not in good condition, it is best to seek specialist advice to rectify the damage before considering applying any plaster to the surface.

However, if the brick wall is in good condition, plastering is possible. It will require a lot of preparation to ensure that it is done sufficiently. There are two main options for plastering over brick:

1. Secure Plasterboard to the Brick Wall

By securing plasterboard to the brick surface, you can avoid working with an extremely uneven surface to begin with. Brick can be hard to plaster due to the different levels of the brick and the cement holding it together.

To use this method, fix drywall boards to your brick wall, and then skim over the plasterboards with plaster. This method is a lot cheaper than alternative methods, however, if you do not sufficiently secure the plasterboard to the brick, you may come across some problems in the future.

2. Apply a Sand and Cement Render

Applying a mixture of sand and cement to your brick wall before plastering creates a very strong, and even finish to work with. The plaster will adhere to this surface a lot better than it would adhere to the brickwork.

Although this method takes a lot longer and can be the more expensive option, it is extremely durable and will need less maintenance in the coming years.

Before even beginning the plastering process, it is crucial to clean the wall thoroughly. Brick materials are known to create a lot of dust and debris, especially over time as they crumble. In order to ensure your materials adhere to the brick, you will need to thoroughly brush over the brickwork using wire brushes to make sure the area is clean and there is nothing that may interfere with the bonds of the plasterwork.

In summary, plastering over brick is not impossible, but it requires careful preparation and consideration. It is important to assess the condition of the wall before beginning any plastering work and to choose the right method for the job. By following the steps outlined above, a smooth and even plastered finish can be achieved on a brick wall.

Can You Plaster Over Wood?

Plastering over wood can be a difficult task due to the porous nature of the material. Plastering directly onto wood is not recommended as it will cause the plaster to disconnect from the surface in the near future, which can be costly to repair. However, there are ways to plaster over wood.

One of the best ways to plaster over wood is to use Expanded Metal Lathing (EML). EML is a sheet of metal mesh that provides texture for the plaster to adhere to. It needs to be secured into place using screws or nails. This method is cost-effective and easy to apply.

Another way to plaster over wood is to disrupt the surface of the wood by scratching and creating texture in it. This creates a finish that is more easily gripped by the primer and plaster. However, this method is not always reliable, and the plaster can eventually disconnect from the wooden surface.

If dealing with wooden panels, it is possible to push the plaster in between the panels. The plaster clumps up on the other side and hardens around the back of each panel, essentially hooking it around each part of the wood. However, this is a last resort method and is not always successful or reliable.

In summary, plastering over wood requires some preparation and the use of proper materials. The best way to plaster over wood is by using EML, which is cost-effective and easy to apply. Disrupting the surface of the wood or pushing the plaster between wooden panels are alternative methods, but they may not always be reliable.

Can You Plaster Over Plaster?

Plastering over old plaster can be a simple process, but it is important to prepare the surface properly to ensure a successful outcome. Before beginning the plastering process, it is essential to consider the length of time the old plaster has been in place. The longer it has been there, the more porous it will be. This means that older and drier plaster will absorb more moisture from the new plaster. To combat this, a base coat must be applied to prime the wall.

The most common base coat used is PVA emulsion. This substance acts as a glue, bonding the old and new plaster together. Skipping this step can lead to future problems, such as flaking and cracking, which will require costly repairs.

Skimming over old plaster is the most common method used when plastering over existing plaster. This involves applying a few thin layers of plaster, rather than multiple heavy layers. To prepare the wall correctly, the following steps should be followed:

  • Clean the wall: Ensure that any dust, debris, and grease are removed from the wall, as these can interfere with the bond between the surface and the products applied. If the wall is not clean and a sufficient bond is not created, the plaster may crack and flake.
  • Apply a base coat: Apply a layer of PVA emulsion to the wall and wait for it to dry. If it is completely dry, you will need to apply a second coat. If it is tacky, one coat should be sufficient. With very old plastered walls, it’s a good idea to add multiple coats of PVA primer to ensure that the plaster has a viable adhesive to stick to. After the first layer of primer has been applied, check the wall for uneven patches and bumps and sand them down using fine sandpaper. Do not press too hard, as you don’t want to damage the surrounding wall. If you had to sand down any areas, you will need to apply a second layer of PVA.
  • Apply the plaster: Wait 7-10 minutes between each layer of plaster until the plaster has become a little firmer, and then clean up any problem areas with the trowel. Apply each layer around 15-30 minutes after the previous layer was applied. You want your plaster to be damp, so the next layer can sufficiently adhere to it.
  • Leave it to dry: Before decorating your wall, leave your plaster to dry for at least a week. Sometimes plaster can take up to 6 weeks to fully dry.

If the plaster is very old and damaged, it is important to fix any cracks and holes before plastering over it. Smaller holes and cracks in a wall can be filled using a sealant such as Caulk. Larger holes and cracks will have to be filled with plaster and mesh, which may be a job for a professional.

Failure to fill holes and cracks can create an uneven finish to your newly plastered wall and can even cause further damage in the future, such as cracking, flaking, and the plaster detaching from the surface.

In some cases, if the plaster is severely damaged beyond repair, it may be necessary to remove the old plaster and start fresh. However, this is not often necessary. By following the proper steps to prepare the wall and applying the plaster correctly, plastering over old plaster can be a simple and successful process.

Can You Plaster Over Breeze Block?

Plastering over breeze block is very similar to plastering over brickwork. Breeze block is a more lightweight version of bricks, made from cement and sand. The reason they are so much more lightweight and inexpensive is due to the materials they are made from, and the fact that they are usually hollow.

Breezeblocks tend to be a lot bigger than normal bricks, so are not very often used to build whole structures such as buildings. You are more likely to see them used to create garden walls and structures outdoors, as well as smaller partition walls.

Before starting any plastering project, it is important to inspect the condition of the wall, especially if it is an older wall. Breeze blocks began to gain mass popularity between the 1950s and 1960s, so some structures could have been around quite a long time.

If the wall is over a couple of decades old and is looking on the older side, it is recommended to contact a professional to fix any issues with the wall before applying any materials on it. Failure to do so could result in major structural issues in the future, such as the plaster cracking, crumbling, and flaking from the wall.

If the breeze block wall is relatively new and in good condition, it is recommended to follow these steps:

Clean The Surface:

Cleaning the breeze blocks thoroughly is an extremely important step before adding anything onto it. If dust and debris are not cleaned from the surface, anything applied on top of it will struggle to adhere, causing many issues afterwards.

Use a wire brush to brush away any dirt and debris to prepare the wall for the next step.

Straighten Out Your Wall:

Walls made out of brick or breeze block are never an easy or even surface to work with. The two best options for straightening out the wall and giving a smooth, blank canvas are to either secure plasterboard to the wall first or apply a layer of a cement and sand mixture. Plasterboard is the cheaper and quicker option, as plastering can be done pretty much straight away. However, using a mixture of sand and cement will give a sturdier option which will last longer.

Prepare Your Wall For Plastering:

If the plasterboard option is used, scrim tape should be used to ensure that edges and drill holes are not covered. Apply the scrim tape to any holes and along all seams and edges. This will create a smoother surface once plastered and will also reinforce the seams to add strength to the drywall. If the sand and cement method is used, it is important to wait for this to fully dry before applying any plaster.

Layer The Plaster:

If plasterboard is used, plastering can be done straight away. After applying each layer of plaster, wait 7-10 minutes and clean up any uneven areas. Wait 15-30 minutes before applying the next layer. If cement and sand are used, once it is dry, apply a layer of PVA emulsion to the wall and wait for it to dry. The PVA should be tacky once dried, if not, apply a second layer.

Once the PVA is tacky, apply the first coat of plaster. Wait 7-10 minutes after applying each coat of plaster and then clean up any uneven areas. Apply each layer of plaster 15-30 minutes after the previous layer.

If there is not enough time to finish the project in one day, it is important to apply a thin layer of water over the plaster before applying the next layer. If a new layer is applied to plaster that is already fully dry, it will not bond. Once the plaster is finished, wait for at least a week before decorating.

FAQs

When it comes to plastering, there are many questions that arise. Here are some frequently asked questions that can help you with your plastering project.

What’s the best plaster to use?

One of the most common types of plaster used when decorating is ready mix plaster. This type of plaster gives you the perfect ratios of sand and cement, meaning you only have to add water. Ready mix plaster is great for DIY jobs as it allows you to be precise without having to think too much about it.

How long does plaster take to dry?

Plaster can take up to 6 weeks to fully dry. In most cases, professionals advise that you wait at least one week before decorating a wall that has been freshly plastered. The drying time of plaster depends on the surrounding conditions, for example, weather, airflow in the home, whether your heating is on.

Try to keep windows in your home open to allow constant airflow through the building, this will help speed up the drying time naturally. Try not to use your central heating for the first 48 hours as drying out the plaster too fast can cause cracks.

What should I do if my brick wall is crumbling and I want to plaster it?

If your brick wall is crumbling, you should not apply any plaster to it. Seek the help of a professional to fix any issues with the wall before moving ahead with your decorating. Plastering over a crumbling wall of any material can cause serious structural problems in the future. Plaster could crack, flake, and detach from the wall behind it.

How do I prepare a surface for plaster?

The first thing you should do when preparing a surface for plastering is to ensure it is clean. A wall covered in dust, dirt, and grease will not hold bond with the plaster, which will cause it to flake, crack, and come loose.

Clean your surface with a sponge and slightly soapy water to remove any dirt. Even if you can’t see it, chances are it is there. The second step you must take is to determine whether your wall needs a primer layer first, to create an adhesive surface for the plaster to stick to.

Is an artex wall or ceiling dangerous?

Artex is generally considered to be safe unless it has been disturbed. This is why it is better to plaster over an artex surface than to remove it. Artex dust and particles contain low levels of asbestos, which can severely damage your lungs and cause complications.

If your artex wall or ceiling has been around since before the 2000s, it is likely to contain asbestos, however, always check with a professional before deciding the best options.

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