This is a 30 year old house that had it's roof replaced 6 years ago for $12,000. Shortly after it was replaced, the homeowners' began noticing black streaks and starting searching for another option to roof replacement. They found my website on Google, called me for an estimate and quickly accepted my bid for non pressure roof cleaning.  The man of the house was curious as to how I was going to acheive the results I am advertising, with the use of a non pressure system instead of a power washer. He was so interested, he watched the entire process from a chair in his yard! When the process was complete, he was very happy with the results and the fact it was completed for a fraction of the cost of roof replacement.  In addition, the following day, I received a call from his neighbor who also wants an estimate.