Michelle asks: “I had black granite floor tiles put down in my bathroom recently and they were sealed after they were put down but i have just noticed several splash marks that will not wash off. The only cause I can think of is that when my husband was painting he washed brushes out in the sink and this splashed onto floor. Could this have caused it and can they be restored or will I need to replace the damaged tiles.”

Here’s our response:

Without knowing the precise nature of the splashes it is difficult to advise, but any impregnating sealer will be beneath the surface of the stone, so it will not stop splashes from getting onto the surface and a fraction of a millimetre into the surface itself.  In fact the sealer will hold a splash at the surface longer than it would be there if it were not sealed, allowing the water to evaporate and leave behind what ever was dissolved ion the water (e.g traces of paint). It could equally be hard water deposits from plain old water, or if your husband used a spirit/solvent based paint brush cleaner then it could have got deeper, through the sealer.

I would first try a basic high alkaline cleaner like Xtreme Clean with the addition of some Microscrub to help it get into the surface. If is it is hard water deposits, then a slightly acidic cleaner like Phosphoric Acid Cleaner may be required. Hope this helps

Copyright Ian Taylor and The Tile and Stone Blog.co.uk, 2013. See copyright notice above.