Do tiles need to be sealed?

Natural stone (marble, granite, slate, travertine) is porous, as is unglazed ceramic. Porcelain, being denser, is generally not porous, although polished porcelain can be, as the polishing process itself can open up tiny pores on the surface. Any liquid spilt on the tile is therefore liable to soak into the tile and cause permanent staining.

However polished porcelain can be treated at the factory to make it impermeable, and in fact we do not sell any porcelain which needs sealing. Nor do we sell unglazed ceramic, so the only tiles we sell which do require sealing are natural stone. There are some exceptions with this too, for example some mosaics are sealed at the factory, so always ask for advice when making a selection.

There are two types of sealant – the surface sealer which coats the surface of the tile, and the penetrating sealer which is absorbed into and fills the pores of the material. The penetrating sealer is a permanent treatment, whereas the surface sealer will wear and require re-treatment after several years, but it can also be used to give the stone a satin sheen.