Hi
A few days ago I liad white ceramic floor tiles, the next day dark patches appeared under the glaze , some tiles went completely dark , after three days the dark / damp patches have not dried out, the tiles wrer laid on thermal board with electric heat matt on top, rapid set adhesive was used as supplied by the shop, any ideas what has caused this and how can it be rectified.
Many thanks
A few days ago I liad white ceramic floor tiles, the next day dark patches appeared under the glaze , some tiles went completely dark , after three days the dark / damp patches have not dried out, the tiles wrer laid on thermal board with electric heat matt on top, rapid set adhesive was used as supplied by the shop, any ideas what has caused this and how can it be rectified.
Many thanks