white limestone discoloration after cleaning, please help

[seb seb]

thing is that before cleaning there was no signs of this stains, after cleaning they have appeared. I have used a mild alkaline-based cleaner which should not make discoloration. . Or do you thing that the stains were there but because were dirty the stains were not visible? those tiles are about ten years old.

 

[seb seb]

first photo is before

second is after cleaning

 

[DHTiling]

How long after cleaning did you take the pics..?

 

[enduro]

Did you do this floor today?

 

[enduro]

Beat me Dave...I think it is still drying from cleaning.

 

[seb seb]

just after, but I went there following day and the same, and i went there today and still the same. i was thinking that it might go after few weeks, but to leave them for few weeks i would have to seal them but if i seal the tiles now before i find out what caused the stains, i will have to remove the sealant again if the stains dont go away...

 

[enduro]

The floor could of had a color intensifier applied to it when it was installed and you have removed most of it from the stone but not all of it. Did you use Tile Doctors sealer & coating remover?

 

[seb seb]

yes, first I have used Tile Doctor Pro-Clean Tile, Stone and Grout Cleaner and I saw the stains than I have used the sealer remover to remove the sealer and then I used again Pro-Clean Tile, Stone and Grout Cleaner and NanoTech Ultra Clean penetrating Tile & Stone Clean. then I thought that I removed just some of previous sealer and I decided to get the scrubbing machine to remove all the sealant and then I have repited the cleaning method as before and still the same. I tried today to use sand paper and the got a bit better but stains still there. I dont know what I should do next. House is still empty but everyone is coming back next week and I have to resolve the problem before I seal the tiles.

 

[enduro]

Where is the job?

 

[seb seb]

South London