I’ve noticed that lichen has started growing on my asphalt-shingle roof. Will it damage the roof? If so, how do I get rid of it? Bleach?
On a related matter, does mildew on asphalt shingles shorten the life of the shingles, or is it just a cosmetic problem?
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Until last year the best solution to moss or lichen on shingles was Tide laundry soap with bleach. Many manufacturers recommended it. But fashion has done away with powdered detergents and all that is available are bottled versions that don't work. I'd suggest using a commercial moss killing spray available at hardware stores. Some advertise as being safe for roofs. As everything that goes on the roof ends up in the storm water system, you might want to check that the ingredients aren't too horrifying.
Just bought an 8.8 lb box of Tide with bleach yesterday for just this purpose. (works on my driveway moss as well) Walmart was the cheapest, but almost every grocery store in my town carries the stuff.....
Life is Good
Ahh, I hadn't thought of Walmart. I will go stock up. All our local grocery stores have gone entirely liquid. The have the temerity to call it "concentrated" when they are really just shipping water along with the detergent now.
Do an advanced search on " roof lichen". You will get a number of threads and a number of helpful references
Spray it with Dis-liken
A strip of zinc (or copper, or lead) along the ridge will kill anything growing on the roof and keep it from growing back. Unless you're in an extremely humid environment, like Florida (hint--fill out your profile!).
Nope.Fresh roof, fresh zinc strips, bumper crop of moss on the shady side in just a couple of years.I low-power pressure washed to remove the bulk of the moss and then used a garden sprayer to saturate the roof with bleach:water at 1:3. All the liquid evaporated so no run-off and no regrowth at all in two years.
Old timers in the woods here used to stretch a bare #12 copper wire across the roof just below the ridge. They told me it worked .. no first hand experience, I use the Tide .
Life is Good
And where exactly is "Lotusland?"
Close to "Jungleland" in Joisey
Thanks very much for the answers everyone!
B.C. More specifically, the rain shadow on the east side of Vancouver Island.
There goes my high-humidity argument.... Maybe you don't get ENOUGH rain to wash the ions off the metal?
We do get rain, just not as much as the west side of the island or the mainland across the Strait.The roof is 12:12 with ridge approximately on east-west axis and the latitude is 49 degrees. Needless to say, there is very little direct sun that hits the roof. Apparently moss likes that much more than it dislikes zinc.