Removing tiles can be time-consuming and messy and it requires the correct tools and equipment. In some cases, the tiles can be stuck solid. This might mean you need an SDS drill with a chisel bit to remove them.
As a potential alternative, you might consider skimming plaster over them, especially if the tiles are firmly stuck to the wall. But is this good practice? Are you able to skim over tiles, or should you just spend time removing them?
The general advice is to avoid skimming over tiles where possible. This is because tiles usually have a smooth surface, meaning the skim is unable to form a solid bond to the tile. Therefore, it is recommended that you remove the tiles completely.
However, in some instances, and with the right prep work, it is possible to skim over tiles. This will require prep with a bonding agent. But even then, there is still a risk that the plaster could fail over time.
Why tiles are not a good surface to skim on
When plastering, to achieve a long lasting finish, it is important the plaster can bond well to the surface. Plaster might initially stick to a wide variety of surfaces, but for it to adhere correctly, it needs to get a good grip.
The problem with plastering over tiles, is they tend to have a smooth and shiny surface. These kinds of surfaces are not suitable for plaster.
For plaster to grip correctly, the surface needs to have a key. This means that it has a rough texture, which will allow the plaster to dry and get hold of the sub surface.
With that said, if you really need too, there is a possible way to skim over tiles. However, you must carry out the correct prep work, in order to produce a decent key. We will look at how this can be done below.
Can you ever skim over tiles?
As we have already mentioned, it is recommended that you remove all tiles and take the wall back to the subsurface. It might take time, but it will enable you to skim the walls and achieve a good quality finish that will last.
However, if for some reason it is not possible to remove the tiles, you can attempt to plaster over them. It’s possible that you’ve been asked to skim over them, in which case removing them is not an option. Or maybe there is a risk of damage being caused during removal.
Either way, you do have an option, but it is crucial that you take the correct steps and prep the tiles properly.
Before you skim over the existing tiles, you need to create a key for the plaster. This will enable it to bond firmly to the tiles.
Before you carry out any work, it’s important to check that the tiles are still firmly stuck to the wall. As long as the tiles are secure, it is then possible to apply a bonding agent.
Two good options for this are Blue Grit or Thistle Bond-it. These products contain an aggregate that when dry, create a rough finish that’s suitable to plaster over.
While it’s not recommended as a first choice, if you are unable to remove tiles, this process should allow you to plaster over them and provide a good quality finish.
Can you skim over tile adhesive? Prep before plastering
If you’ve chosen to remove the tiles, you’ll often notice that there is tile adhesive left behind. Tile adhesive can be difficult to remove completely without damaging the wall. As a result, you might choose to skim over it.
The aim again here, is to ensure you carry out the right prep work. This will allow the plaster to bond to the surface and ensure that there are no imperfections in your skim coat.
Before you start to skim, try to scrape off as much adhesive as possible. Your skim coat will only be around 2-3mm thick, so any high spots of adhesive will need to be removed..
Once the tile adhesive is ready, and as smooth as you can get it, a bonding agent can be applied over the wall and remaining adhesive. If required, you can use a coat of PVA followed by a coat of bonding agent, although this is not always necessary, but it can help to produce a better surface to skim. Once the bonding agent has dried, it is then possible to apply your skim coat of plaster.
Conclusion
Removing tiles can be a lengthy and messy job, but it’s usually the best course of action. By removing the tiles and the majority of adhesive, you should be able to achieve a good finish, that will stand the test of time.
If you have no other option and need to skim over tiles, then it is possible with the right prep work. However, we must stress, this is not the best option and should be your last choice.
