Gang, this developer went the cheap route and hired the competition to clean and seal limestone.  This is what they did

1) install and sealed with 511 enhance and seal
2) applied grout ( cementiuos) and immediately, added second coat of 511 enhance and seal
3) next day moisture all on grout lines so they decided to use an alkaline stripper to no avail

I told developer that this may be a case for Mr. Jack Hammer. Have you guys  ever corrected a situation like this ?

Thanks guys very high end would work wonders if I can find solution

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