The Roof Cleaning Institute Of America Training & Certification Forum
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The rumor that bleach can cause shingles to dry out and crack has been spread by companies to sell their " green products". When confronted with this rumor I state that shingles have moisture "on" them that the salt in SH does dry out. Therefore removing the moisture that the algea need to survive along with the algae its self. If salt dried out and caused shingles to crack then how could any shingles last more than a few days on the coast line. After all the rumor is that after only one application the roof will dry out and crack. I have resurched roof cleaning for a year and a half now and can not find one bit of proof that the rumor has any merit . Not one picture, not one study, nothing. Of all the articles and reports that claim this rumor as fact ,why is there no proof?  Well, what do you know, it must be a rumor.