The Roof Cleaning Institute Of America Training & Certification Forum
"Find A Certified Roof Cleaner Directory"

To me its all about getting to the customer. In the winter getting your roof cleaned isn't #1 in your mind. Once it warms up people start getting outside and looking to do some work to the house.  Most of the winter cleaning is going to be sold by talking to the homeowner face to face. They aren't going to call you this time of year.