Just curious to see if anyone has an efflorescence clause in their contract. I have never had a problem before with the issue that a little paver prep couldn't take care of, until this week. We recently finished a 1700sqft patio that has a VERY anal owner. One of my favorite patterns (...yeah Right!) 45 degree porkchops, and there is white on alot of the pavers. I have already cleaned the patio twice, going stronger the second time and still some will not come out. Of course the owner wants to hold back payment until the "issue" is resolved. Anyone ever run into this problem?