Special, 2-component epoxy resin for the pre-treatment of mineral, asphalt and other substrates. Especially suitable as a surface applied membrane to suppress retained or residual moisture in cement/sand screeds and concrete up to 98% Relative Humidity (Rh). Thomsit R 755 can also be used to repair cracks, improve the integrity of porous or friable substrates and as a bonding agent for Thomsit SE 93 Rapid Screed Cement. Not suitable as a structural DPM or where there is a potential for rising moisture under pressure, e.g. where no effective structural DPM exists.