The Sunday Times Newspaper, March 24 2019, “Want to restore your old stove or create Moroccan-style plaster walls?”
A Tadelakt is a traditional waterproof plaster finish from Morocco: as you say, it looks and feels like polished concrete. It was used by the Berbers to waterproof earthen cisterns for storing drinking water. In Morocco, public baths and bathrooms are still finished this way. The lime plaster is made waterproof through its inherent properties and the application technique. The olive-oil soap that is rubbed into the surface reacts with the lime to form calcium stearate. This results in a surface that is durable, as well as water- and scratch-resistant. It’s also sustainable.
Only employ experts who are trained to use it. We used tadelaktlondon.co.uk. It costs £120-£150 a sq metre, including labour.