Additive for plastering mortar

An additive for plastering mortar. Raw material formula of the additive contains 2-3% of Hydroxypropyl methyl cellulose, 2-3% of polyvinyl alcohol, 2-3% of polyacrylic resin, 3-5% of naphthyl sulfonate formaldehyde condensate, 30-40% of light calcium carbonate and 40-50% of bentonite. By optimal combination of multiple polymers, water retention capacity and bonding strength of pre-mixed mortar of the product are enhanced, and waterproofness of hardened mortar is improved. In addition, the wall is endowed with a self-breathing function. Existing properties and characteristics of plastering mortar are enhanced. The additive is helpful for sustainable long-term self-curing of cement mortar by the utilization of water vapor in the environment. It is guaranteed that strength of plastering mortar is performed to the maximum.