Has anybody tried post treating with copper salicylate for algae / fungi prevention?
I’m not a pressure washer, but I dabble in some construction, and I stayed at a holiday inn express before.
If this is the powdered copper stuff that you get from the pool place I wouldn’t use it. Does copper help stop algea from growing on a roof - yes. They don’t recommend this, they recommend using bleach and water. The powder will just wash away with rain and blow away with the wind. SOme of that stuff has some nasty health issues (don’t know which one your looking at).
From ARMAs site - linky link - https://www.asphaltroofing.org/algae-moss-prevention-cleaning-asphalt-roofing-systems/
Other preventative measures —such as adding zinc or copper strips to prevent both algae and moss, or applying asphalt shingles that incorporate algae resistant copper granules —may be employed when it is time to replace a roof. Currently, there are asphalt shingles available that use algae resistance technology.
Adding zinc or copper strips to an existing roof is not recommended since this will require either applying the strips with exposed nails (which can cause leaks over time) or breaking the sealant bond (which may eventually result in wind damage) to slide the strips under the shingles.
Hope this helps some.
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I cleaned a roof last summer where the guy had used the algae resistance shingles. He also installed strips of copper under the row of shingles near the peak with about a 1/4" sticking out past the edge. Both methods failed to prevent algae growth. I think he did get a little money from the shingle manufacturer for a warranty claim to help recoup some of the cost of cleaning but that was it.
As far as the original question I think @CaCO3Girl can probably give some good info on it. If I remember right I think we talked about it in the past and it’s supposedly some nasty stuff. I might be thinking of a different chem though.
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The stuff I have seen was in liquid form, and apparently approved for organic gardening. I’m not sure what the trade name was.
I might be thinking of a conversation we had on here about the chems in that Spray it and Forget it stuff. If the stuff you’re talking about can be used in organic gardening I’m definitely thinking of a different chem. I think the chem in that Spray it and Forget it is a herbicide or pesticide and is bad for aquatic life or something like that.
I don’t believe most of us on here use anything like copper salicylate for post treating. In my area just using regular house wash mix does a pretty good job of preventing algae from coming back as fast. I know that doesn’t answer your question though. I’m sure our chemist will chime in and give you some info about it.
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Yeah, thats what ARMA says, and they are probably upselling those algae resistant shingles at a premium. I haven’t used them. Interesting. I wonder why only 1/4", I think, but I would have to check, that an inch would have to be exposed for the copper to work. I wonder if he used copper flashing or some other copper. Some old timers say that this algae never happened with the old lead flashing, but I wasn’t alive for that and their memories might be fuzzy. zinc is supposed to work too. From my limited understanding, they are just putting these metals in the shingles. I’d have to look it up though.
Okay, I read up on it. Basically it’s a non water soluble acid. It’s also environmentally hazardous.
The spray and forget stuff is also an environmental nightmare and says right on the pesticide label not to let it get into the environment.
Would zinc or copper or lead plates help…sure, because they are solid. Algae and fungus need cracks to grow in. This is basic substrate thinking. Put a flat non porous metal on a roof where fungus can’t dig in, and when the rain comes it washes away anything that tried to grow there. Hard plastic would probably work too. Anything that doesn’t have tiny little nooks for the fungi to hide. Normal roof shingles provide those nice nooks where the fungus love to take root and grow.
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