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Roofing/Roof moss control



I am interested in controlling/eliminating moss on my concrete tile roof here in Central Oregon. I want to use either copper or zinc or galvanized strips which will be inserted just beneath the top-most tier of tiles (at the roof line) and then down 4 to 5 more tiers, repeating this insertion process until I am close to the gutters.

My main issue is that I can't seem to find someone that can tell me what is the best product to use and the thought processes as to why one material is better than the others.  I would like to do this only once, if reasonable, as roofs and ladders and me have an adversarial relationship.  Thank you in advance for any help you are able to provide.

Hi John,

do this only once...thats probably not going to happen.

What I know:
As roof surfaces accumulate organic matter they're more likely to support life be it algae, moss or lichens; that organic matter may be invisible to us but is a fertile base for plant life. Roof surfaces are irregular, water wont flow across the planes evenly like water off a sheet of glass, it will tend to flow with more volume and velocity in channels.

Let's say you install copper or zinc strips- within a month or two you'll start to see clean stripes where the moss and algae are being killed; however the stripes probably wont converge to make a clean roof. Water will tend to flow in the same channels leaving the plants in the high spots to continue right along. As time goes by the metal strips will develop an established coat of zinc or copper oxide and will lose its effectiveness as an algaecide. So, for all your effort you had a roof that looked like it was crying for a few years before becoming covered with moss all over again.

If it were my roof I'd use the product in the link below; depending on how much tree cover your property has it may need to be done every few years. It pretty much kills on contact, the plants you're trying to control are fairly slow growing so you'll have a good period of time where your roof is clear.

Good luck,


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Tom Petrilli


I can answer questions about residential and light commercial roofing. I really enjoy solving complicated problems. My expertise is in shingle, slate and traditional metals (copper, lead, terne, stainless) as well as single ply low slope roofing. I have also installed a considerable amount of synthetic slate.


I have been a roofer for 21 years, I've owned my own company for the past 13.

The National Roofing Contractors Assoc and Virginia Association of Roofing Contractors

I have attended numerous manufacturer training programs as well as sought out experts in specialized work for instruction.

Awards and Honors
A+ rating from the Better Business Bureau, A rating from Angies List, highest mark for quality and value from the Washington Consumer Checkbook

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