High humidity or damp pavers can cause a white haze residue on the top of the pavers, make sure that the pavers are completely dry before installing the paver set sand and try to work on low humidity days. If you are unable to work on low humidity days and the humidity is high, work in small sections and do not allow the sand to remain on the surface for long periods of time. The improper cleaning of the paver surface prior to the application of water can also cause white hazing. A fine bristle broom cleaning and blowing with a leaf blower until dust does not rise from the surface is required before the application of the water activating the product. The dust should be sweep and blown from several different directions to remove the dust completely. If the paver or stone you are using is textured the use of a leaf blower on the surface after the final watering will help prevent white pockmark type staining. This type of staining forms due to the ponding of water in the clefts and crevices.
There are a several known ways to help remove the staining of the pavers if it does occur even after all the above steps have been taken. All of these methods below will require some elbow grease, a hard bristle brush and may take multiple times to get rid of the staining, see below:
1) The first method for removing the hazing is a 50/50 mixture of warm water and household vinegar. This step usually only works when the material has been down for a short period of time, usually within a couple of days.
2) The second method is to use efflorescence or TSP (Trisodium Phosphate) cleaners, mix with warm water. This usually works if the product has been down longer than a couple of days.
3) The best way to remove the paver set sand from the paver surface is to use a hot water pressure washer at 180°F. The heat will reactivate the polymers in the product and allow the sand and hazing to be removed. If doing a smaller area you can use boiling water.
4) Another way is just to leave the staining and it will weather away naturally with time and rain.