Tadelakt and Tadelakt Soap
Tadelakt plaster is a traditional Moroccan surface finishing that has been in use for around 2,000 years and offers a very distinctive look that is similar—but not the same as—Venetian plaster. If you have ever considered this remarkable plaster for your walls, ceilings, or even sculpted areas like baths and sinks, then you may have heard of Moroccan black soap, which is frequently used with Tadelakt. But what is? And why is it so important?
Moroccan black soap acts as a sealer for Tadelakt plaster, which hardens the plaster and gives it water-resistant properties that it would not otherwise have had.
What is Moroccan Black Soap?
As the name suggests, Moroccan black soap is a soap that originated in Morocco. It is a high-alkaline soap that is made from olive oil and macerated olives, which is why “olive” is prevalent in the names of so many brands of Moroccan black soap. The soap has a dark greenish-black color, similar to the olives used to make it.
While this kind of soap is popular for moisturizing and exfoliating skin, it is its role in the process of applying Tadelakt plaster that we are interested in here. It is also worth noting that there is an African black soap as well, but these two soaps are not interchangeable, since both the ingredients and the manufacturing process for each are different.
Why is Moroccan Black Soap Important for Tadelakt?
Tadelakt is a type of lime-based plaster that has been used for thousands of years. The use of lime in this context provides many advantages over more modern alternatives, such as a natural resistance to bacteria and mold, as well as a breathable quality. However, one of the most popular uses for Tadelakt is rooms that are traditionally very moist, such as bathrooms. Unfortunately, Tadelakt is not inherently waterproof, which is where Moroccan black soap comes in.
When mixed with water and applied to Tadelakt, Moroccan black soap gives the lime-based plaster a shiny, water-repellent surface, making it both easier to clean and more suitable for use in a wet room. In some cases, the finish of Tadelakt that has been treated with Moroccan black soap can be almost glass-like in smoothness.
Unfortunately, black soap is not a one time deal, and the unique and desirable finish that Tadelakt plaster presents when it has been treated with black soap needs to be kept up with repeated applications. The exact interval may vary, but it is generally around one or two months.
During the period between applications, it can help to be aware of any “matt” patches in the Tadelakt, since they are regions where the soap coating was perhaps not as thorough as the other areas where the plaster was applied. Of course, having to re-apply black soap to your Tadelakt on a regular basis is not ideal, but the process of applying it is not especially difficult, and could easily be taken care of without the need to hire a professional.
It should also be noted that if you do not have Tadelakt installed in a wet room, you may not need a black soap treatment, depending on what look you are going for.
What are the Benefits of Tadelakt for a Wet Room?
Beyond the look of Tadelakt—which we understand is subjective and not guaranteed to appeal to everyone—there are several material benefits to using Tadelakt over more modern alternatives. We have mentioned that it is naturally mold resistant and breathable, of course.
A less obvious perk of Tadelakt is the fact that it is more environmentally friendly than modern alternatives. For example, Tadelakt releases around 80% less carbon dioxide than cement-based finishes. On top of that, lime absorbs CO2, meaning that what carbon dioxide it does release is offset by later reabsorption.
Given the damage we are doing to our environment with excessive levels of CO2, this should be seen as a positive. It also does not require any chemicals in the manufacturing process, something that often damages the environment in subtle and not-so-subtle ways with synthetic alternatives.
Visually, Tadelakt is a very versatile finish, with several different looks being achievable with little more than pigmentation applied to the mix, or a different application style. It is for this reason that experienced Tadelakt plasterers are highly sought after.