There are actually several things that cause exterior surfaces to become discolored, and they all impact certain areas more than others. The big causes of hardscape staining are: mold/fungus, tannins, pollution, moss, and plain ol’ dirt. Let’s take a look at each of these factors so that you can get an idea for what might be causing the discoloration on your own surfaces.

Soft washing and pressure washing are similar methods of removing gunk, moss, staining, and debris from exterior surfaces, but there are important distinctions between these two methods.