# ATCO Shakelast roof preservative



## florthil (Sep 10, 2013)

Hi,

I am a new homeowner and my home has a asphalt composite shingles. I live in seattle and because of the wet weather we have here, I have moss growth on my roof. I am trying to hire a roof cleaning company to take care of it. While most roof cleaning companies say they use Zinc Sulphate based moss prevention, I have one company that uses "
ATCO Shakelast roof preservative". From what I researched it is a Copper naphthenate based product. The vendor says this kind of moss prevention will be good for anywhere between 3 to 7 years. While I like the sound of it, I couldn't find much details about it and not sure if its a common approach for a composite roof. 

http://www.pesticideinfo.org/Detail_Product.jsp?REG_NR=00102200518&DIST_NR=003486

1. Is copper naphthenate based product good for my roof?
2. is there any downside that I should be aware of?

thanks!
Murali


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