I have recently had my house renovated, and had underfloor heating put in. In the kitchen, hallway, utility room and small study room, we have had white with grey marble effect tiles layed, with a high glass sheen and the make is colour-tile (glazed vitrafied tile) with a velvet finish. Over the past few months, brown stain marks have started to appear in the middle of the tiles and they are getting darker and more frequent as time progresses. I have been advised this could potentially be because the adhesive (the wrong colour or not allowed to go off). Would anyone know if this is correct or have any other suggestions? Many Thanks in advance.
