In a brick wall backed with a CMU wall, what is the thin coat of mortar used for waterproofing called?

The thin coat of mortar used for waterproofing a brick wall backed by a CMU (Concrete Masonry Unit) wall is known as parging. Parging serves not only to enhance the aesthetic appearance of the surface but also plays a crucial role in providing a waterproof barrier. This application helps to prevent moisture from penetrating the walls, thereby protecting the integrity of both the brick and the CMU behind it.

Parging typically consists of a mixture of sand, cement, and sometimes lime, applied to the exterior of masonry walls. This method is effective in sealing the pores of the concrete and protecting against water intrusion, making it an excellent choice for situations where moisture control is a concern.

In contrast, stucco is often related to a thicker finish used primarily for decorative purposes rather than waterproofing layers, siding refers to materials placed on the exterior of a building for cladding and insulation, and rendering generally refers to the application of a mixture over surfaces, but it isn’t specifically the term used for the thin waterproofing coat in this context.