Tadelakt

Fictional Arab people South Arabian deities Tadelakt (Moroccan Arabic: تدلاكت, romanized: tadlākt) is a waterproof plaster surface used in Moroccan architecture to make baths, sinks, water vessels, interior and exterior walls, ceilings, roofs, and floors.

It is made from lime plaster, which is rammed, polished, and treated with soap to make it waterproof and water-repellent.

[2] Since it is applied as a paste, tadelakt has a soft, undulating character, it can form curves, and it is seamless.

"[3][4] Tadelakt is thought to have evolved from qadad, a similar plaster used in Yemen for millennia that is treated with calcium hydroxide and oils and fats instead of soaps.

Traditional application includes polishing with a river stone and treatment with oleic acid, in the form of olive oil soap, to lend it its final appearance and water resistance.