Description :

Ardex E655 is a water dispersion primer and additive designed to improve shear and tensile bond of sand/cement screeds, plasters, render mortars and tile adhesives. It is use for treating porous substrates and materials.

Thus, it can be used as a primer and additive to prevent gypsum substrates from breaking off from the chemical reaction between gypsum and cement aluminates; and to improve strength of cement/sand, mortar/screed.