Shado wrote:I use only the pressure sprayer to clean the "pebbled" driveway, sidewalks (foot paths) fence and just about any other concrete type surface. It works well with just the water pressure and no chemicals or detergents. 100 bar (1,450 psi) works just fine for me. My unit is a just a small one (Bosch Aquatak 100) but well worth the 3,000 baht investment.
After I cleaned the pebble drive way really well I applied a clear sealant over the surface. Can't say that it prevents the black mildew but it makes for quicker and easier cleaning.
Shado, where did you buy the pressure washer?