Page 1 of 1

Black Spots On Patio

Posted: Mon Sep 15, 2008 1:04 am
by chewit
Hi

Today i power washed my natural stone(untreated) patio. It was covered in green algae. Once cleaned I was left with black spotted slabs. The pressure washer could not remove and in fact they did not scratch off!

Please, someone save me from my polka dot patio :(