Primus is a 100% acrylic-modified product, which is field mixed in a 1 to 1 ratio by weight with Portland cement to produce the Primus mixture.
The Primus mixture is used to adhere insulation board to an acceptable substrate and to embed Dryvit reinforcing mesh as part of the base coat for Dryvit systems. The Primus mixture can also be used as a skim coat to produce a smooth level surface on masonry or concrete.