Porcelain tile stain of some kind

Hi all,

We purchased some porcelain tile through special order from one of the large home center stores. The guy who is installing the tile is about halfway through the installation and I've noticed that some of the tiles have this white, powdery, checkerboard marking of some kind all over the surface. It appears to be an indentation marking from the back of the tile that was stacked on top of it in the box. I don't know how the tiles were stored but judging from the condition of some of the boxes, it appears that some of the boxes may have gotten wet when the tile was in storage.

The main problem is I've used no-rinse floor cleaner with a regular mop; a nylon scrubbing pad; and a larger scrub brush to clean the floor and I can't get rid of the markings. I even applied chlorine bleach with a sponge to one of the tiles and the markings were not removed. The checkerboard markings disappear when the tiles are wet but then reappear once the tile dries.

Needless to say, I am absolutely furious that I have this partially installed floor that is unsightly, to say the least. I'm about ready to go storming into the home center store to demand that they replace the floor and tile since they sold me this flawed tile in the first place.

Any suggestions as to what cleanser or technique I should try to remove this imprint or stain from the tile? The tile has only been installed for 24 hours so I wasn't sure how long I need to wait before trying harsher chemicals or more abrasion to remove these markings.

Thanks for any help!

 

Try some TSP, found in the paint section. If that does not work, go and complain. I know the markings you mean, but i have always had them wash off with no problem. I dont know whats going on there.