Lately I have come across many paver installations with efflorescence. I believe a lot of it is occuring because of the increase in raw material prices and that paver manufacturers are substituting inferior admixtures or leaving out some altogether. Here is I deck I salvaged recently:
This is probably the worse case I’ve ever seen. These pavers are so porous, a cup of water disappears almost instantly. What that means is the sand underneath remains perpetually wet. This patio area, although it did not get rain, was soaked and the pavers never became dry. The efflorescence had begun to disappear on the exposed pavers, but without treating it, the customer had begun to apply an acrylic sealer. Because of the moisture content, the sealer had immediately started to turn milky. We first stripped the sealer, then treated the efflorescence. Since we wanted to make sure the efflorescence was gone, we set up fans on the pattio and came back the next day. The pavers were still wet, which meant the sand underneath was still soaked! We were able to get the surface dry enough and applied an efflo-blocker treatment, then sealed. The results? Well, you decide.
Here is the best article I’ve seen yet on the subject. http://www.pavingexpert.com/eff01.htm
When you have new pavers installed, don’t have them sealed for 30-60 days. That way the calcium carbonate can exhaust itself. If it doesn’t rain, especially under a roof, you need to wet them with a hose. Do it several times. Then treat with a commercially available efflorescence treatment. Follow the directions carefully, this stuff is hazardous and can harm you or the pavers if improperly used! Then seal your pavers with Seal ‘n Lock. Or you can call us or a qualified contractor in your area who will seal with Seal ‘n Lock.