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

This is an old, almost "forgotten" wordpress roof cleaning blog I hardly pay any attention to.

But, since it is an old URL, Google "trusts" it 

If you go to http://roofcleaningtampa.wordpress.com/category/tile-roof-cleaning-tampa/ and scroll to the bottom of the post, you can make a comment, and possibly get a backlink from Google.