About 6 months ago we had red/blue reclaimed Victorian tiles laid in a checkerboard pattern outside the front of our house. Red dust seems to be constantly coming off the red tiles, so that the grout looks pink, and it will even tread indoors. Now on one of the tiles the smooth surface seems to have come away about the size of a 50p piece.
Does any one know what might be causing this (wrong bed? wrong grout? need treating?), these tile must be a hundred years old, and seemed in fine condition before laid.
Perhaps unrelated, but might be: we frequently find a white salt-like deposit on the surface of the tiles - almost like you might expect after the snow melts in winter and the gritting salt is left behind. There hasn't been any salt around, and so I don't know where this is coming from. It brushes off by hand easily.
I had an "expert" come and look at them, and he thinks the efflorescence and crumbling are not related. He wonders if they are particularly soft, and are not sealed and so they are simply wearing away because of that. He is also suspicious that the glaze/surface may have been missing on some of them when they were laid, and so we are simply just picking up on it now. I had a couple that were left over from laying and they are ok, but not all the tiles may be identical. He noted that not all the red tiles seem to have faired as badly as each other.
I also did manage to get hold of the person who laid them, and he is also planning a visit. He thinks they probably need sealing.