I have a concrete drive lined with large oak trees. They stain the
driveway and about 40% of it is black. In the past I've used a
pressure washer which works great. The driveway is bright and new
looking. It is ready to be blasted again, but I am wondering if maybe
I am doing more harm than good. I know better than to pressure wash
an asphault shingle roof, but what about my concrete driveway? If I
use a garden hose, it only gets it slightly clean. It will go from
black to a dark grey.
I don't want to use harsh chemicals, since it may kill the grass along
the edges. And the drive is very big so it would take lots of
chemicals - it takes all day to pressure wash.