Kevin
lets stick the floor in question topgun has not said what it is
so that still needs to be established.
Anyway floor stripper and high alkaline cleaners on there own wont do any harm on there own
but when you introduce scrubbing action as said earily in post, this will dull down a polished floor and remove any sealer that is on the top of the floor.thus causeing the floor to look duller
when you scrubb the grout lines with a scrub brush plus stripper and high alkaline cleaners it may well dull them areas around the grout lines If this happens he needs to re do the whole floor to get the same finish.
if topgun dose not know how to refinish the whole floor he has a problem on his hands
with topguns floor i will hazzard a guess that it is tumnled or antiqued finish and the tiler has applied to much, poor quality sealer and applied it unevenly this may be why the grout lines have turned yellow in certain areas
kevin to answer your question which type of floor can you can have this problem on,, all of them
is the answer just because you use a hand held scrub brush dose not meen you dont have a lot of
down pressure.
davy
