After treating corners and seams of cement board with mesh tape and a polymer-modified, cement-based tile mortar, the area should be allowed to cure for at least 24 hours before the application of MAPEI’s Mapelastic AquaDefense. Note: If time is an issue, use a MAPEI rapid-set, polymer-modified mortar with the mesh tape and allow the area to dry for at least four hours before the application of Mapelastic AquaDefense.