The lime used to make this plaster contains some impurities that confer to the material hydraulic properties, meaning that the plaster hardens when mixed with water. This is different from saying that the plaster is waterproof, which refers to the ability to repel water. Tadelakt is often mistaken as a waterproof material, but it is actually the traditional application method that makes it water-resistant. This method involves repeated polishing with a hard, flat stone. This technique, taught in Stucco Italiano’s Masterclass, is not widely used by decorators globally. The more commonly used, easier, and quicker technique involves only a trowel, and is very similar to that of Venetian Plaster. Regardless of the application method, Tadelakt can be made fully waterproof with the right sealer, making it suitable for wet areas like showers.