I purchased a home last year that was built in the late 70's. The floor in the entry foyer appears to be slate. It's multi-color blue, gray. My problem is that it seems to be discoloring and getting worse. For example, many areas of the grayish blue tiles are turning a greenish blue. Almost like paint is coming off but I don't think the slate would have been painted. Does anyone have any suggestions on 1. Whether you've seen this before and this is something I can clean off with something, 2. Whether I can/should paint the tile then seal it? 3. Whether I should just clean and seal it as-is because you think the discoloration is not easy to correct.
Thanks a lot for your input.
i recently read a trade article where the author talked about some cheap slate he installed. The slate was soft and the color was in a thin layer which started to wear over 7 years and has now dulled the colors. I guess a sealer may help to keep the colored layer from further abrading but there is nothing to bring it back to its original state