Glass Mosaic Tile Epoxy Grout Sia Glass Mosaic GROUT is a two part, general purpose, water clean-up epoxy system Sia Glass Mosaic Tile GROUT is widely used for grouting most types of tiles in demanding environments. It consists of epoxy pigmented resin and epoxy hardener. Complies to ASTM C237-82 SURFACE PREPARATION: Before commencing grouting, ensure the tile adhesive has set firmly. This usually requires 24 hours with the majority of tile adhesives. Remove any spacer lugs, rake-out any excess adhesive and any loose or foreign material from the grout joints. In general, ensure the grout joints are clean and dry.