Tiles are not a barrier
Ceramic tiles resist water, but grout and sealant joints do not stop it entirely. In showers and on terraces, the real protection should be a waterproofing layer beneath the tiles, which older properties often lack.
Common signs
Darkening grout, loose or hollow-sounding tiles, failing silicone around trays and baths, and damp or staining on the other side of the wall are typical indications.
Investigating without demolition
Moisture meters with modes suited to plaster and tile can help map wet areas behind the surface, giving a basis for deciding whether and where to open up.
