In a nutshell, yes, you can tile onto a lime plastered wall. Before tiling, make sure that the walls have dried or ‘cured’ as they say.
If, like us, you have lime walls or floors in your home and are looking for the right information on whether or not you can tile on lime look no further.
You might have heard that lime is difficult to bond to. Or that you may need a special adhesive, in order to make things work. But the truth is that there is nothing too challenging about tiling lime plaster.
Believe it or not I actually know a thing or two about tiling. My father did it for a living so I did spend a lot of weekends giving a hand where I could.
Not my most favourite job I must say but a lot of people can overthink it when it comes time to tiling.
Here are a few simple things to keep in mind.
Does the Location of the Wall Matter?
People usually choose to tile their bathrooms, kitchens or even a hallway. Tiling lime plastered walls that are inside the building is always a better decision as there is a risk of cracks developing between the tiles (at the grout joints) which might allow excess moisture to get in.
But it doesn’t mean that you can’t tile a wall that is located outside.
There are plenty of examples of beautiful mosaics that have been laid on the exterior of a building.
Obviously the Irish don’t typically tile outside because of our harsh and rain heavy climate but it is possible.
General Tips on Tiling Lime Plastered Walls
- First things first, you have to make sure that the lime plaster has completely dried/cured (below you will find a helpful table with the estimated cure time for different types of lime plaster).
- Take your time and pick the right tile adhesive (we will talk about adhesives in more detail later on).
- Don’t forget to apply grout – it’s that material that you can see between the tiles. Apply it only after the tiles are set strongly in place. Clay or lime are usually used as a binder material. If you have relatively large joints, then you would need good sand in the grout.
- Consider applying the tiles with a full bed. Don’t simply dot and dab.
- If you can, use thin tiles. Lime mortar will easily hold something that is light. However, the chances are high that you will not experience any problems with heavier tiles as well.
How Long Does Lime Plaster Take to Set?
You should never begin tiling a lime plastered wall that had not yet been set.
One of the main disadvantages of lime mortar for a lot of people is the fact that it might take a while to set. Especially, feebly hydraulic lime that may require a few weeks.
I have honestly heard horror stories of tiles falling off the wall because the Lime has not set or cured for long enough.
Definitely leave plenty of time and more if you are unsure.
Below you will find a table of the estimated setting time for different types of lime.
| Type of Lime | Setting Time |
| Non-hydraulic lime (lime putty) | Doesn’t set in water. Sets by carbonation thus requires a lot of time. Remains softer. |
| Feebly hydraulic lime (NHL 2, Natural Hydraulic Lime 2) | A week or more (in most cases, less than 20 days) |
| Moderately hydraulic lime (NHL 3.5, Natural Hydraulic Lime 3.5) | A few days (however, can take 15-20 days) |
| Eminently hydraulic lime (NHL 5, Natural Hydraulic Lime 5) | 1 day (sometimes, 2-4 days) |
However, you have to bear in mind that the actual terms will depend on a lot of different factors. The realistic curing conditions, at times, can’t be compared to the standard ones.
Temperature, rainfall, and humidity affect the hardening of lime mortar. The variations in these environmental conditions will affect not only the overall setting time but also the structure and internal development of lime plaster.
So, before continuing with the tiling process, make sure that the mortar is set and that the surface of the plaster is suitable to work with.
Which Tile Adhesive Should You Use for Lime Plastered Walls?
Do you need a special type of adhesive to tile onto a lime plaster? Or would regular thinset mortar do the job?
- If the adhesive is a base coat and finish coat, you can usually tile over it.
- However, you can go for a regular off-the-shelf tile adhesive and it will, most likely, get the job done.
- You can also buy a suitable primer to go over the mortar beforehand. An acrylic polymer dispersant might be a good choice.
- A powder-based adhesive helps avoid ettringite reaction, so you might want to consider such an option.
- Your choice of adhesive also depends on the location of the actual wall. For your bathroom, for example, you would want to use a waterproof adhesive.
- When you don’t have a super wet application, you can go for clay mastic. It is a strong and cheap solution that will hold all the tiles in place.
- The easiest way to find out, if the adhesive is right for you, is by reading the label. Adhere Cal by SecilTek, for example, is suitable for the restoration of old buildings and you can apply the thing over lime-based mortars. By the way, this adhesive is based on NHL (natural hydraulic lime).
- NHL mortar is a relatively popular choice when it comes to setting tiles. It reduces the risk of efflorescence and staining. Moreover, the resistance of such mortars increases over the course of time.
Final tip: in case you are not 100% sure whether or not your adhesive of choice is going to work, stick a piece of tile to the wall and let it set overnight. In the morning, you will have the opportunity to check if the bonding went well.
To Wrap Up
Can you tile onto a lime plastered wall? We are pretty much sure that after reading this article, you not only can but also know exactly how to tile onto the lime mortar.
Here are a few important takeaways:
- The location of the lime plastered wall will affect the setting time of the mortar and your choice of adhesive (go for a waterproof option, if you’ll be tiling the bathroom, for example).
- It is crucial to ensure that the lime plaster had fully cured before continuing with any other works.
- Practically any type of tile adhesive is suitable for lime plastered walls. Simply follow the instructions that come with the product.
- NHL mortar is one of the solutions that you can use to set tiles in place.
- Apply the tiles with a full bed and don’t forget about grout.
Congratulations! Now you are ready to put your knowledge into practice.
