A parge coat is a thin coat of a cementitious or polymeric mortar applied to concrete or masonry for refinement of the surface. Pargeting is a more involved process, involving designs in relief created in the surface.
Parging is usually applied with a trowel and pressed into the existing surface. The intent is to create a contiguous surface by filling imperfections such as surface air voids created by bughole-induced outgassing, to level a surface for aesthetic reasons, or to prepare a surface for topcoating with an additional form of protective coating.
Parging is a low-cost alternative to repointing, providing structural cohesiveness to masonry walls whose mortar has begun to fail. Parge coating can also be used to create air tightness for apartments.