I have a lichen and moss problem on the shady side of my roof.
Is this a long term problem?
What is the best way to get rid of it?
If it’s a large amount your roof is probably damaged.
I’ve had success in killing small patches of mossy growth on my north-facing front porch with cider vinegar.
Pressure wash it with a mild bleach solution.
Then use zinc strips to combat further growth.
The zinc carbonate will inhibit moss.
Probably will work for lichens as well, but I don’t have first-hand information about this.
I live in a rain-forest, so I actually know this will work.
wetting with bleach solution and letting it sit might be good.
pressure washing a roof against the grain is not good.
a zinc ridge cap is a preventative, or zinc strips under your ridge cap.
My roof guy says do not pressure wash - will significantly lessen the lifespan.
He cleans off moss with high pressure air and prevents new growth by sprinkling Tide or some other dry detergent (washing soda should work too) to lower the pH.
Zinc is okay for mildew, but not for moss. On my roof with zinc flashing around vents, it was moss free for about a foot below - then the moss started again.
Copper. In Washington State, I was told by an old-timer to combat the “greenies” on roofs (rooves?) the trick is to either install a copper wire the length of the peak of the roof, or to shove bits of scrap copper sheeting just under the edges of the shingles.
Copper sulfate is used to control algae in pools.
It also colors the flames a really neat blue-green in fireplaces!
~VOW
My neighbor inserted a four-inch wide copper strip just under the top row of asphalt shingles near the ridge-line of his roof. About two inches remained exposed. With the price of copper nowadays, it can be rather spendy. Another trick is to glue a double row of pennies on the ridge-line. Yeah, crazy that it may be but it does work. At least you know the dollar value of the effort, plus the cost of a quality glue.
I used to go up on the roof annually and use a wire brush to manually scrub my shingles, followed by a stout factory broom to sweep everything into the gutter. That was all followed by a pressure wash of the gutters to blow it all through the downspouts and into a bucket for later disposal. I’ve since hired professionals to use environmentally-friendly chemicals. But you need to “top up” the process every few years.
It’s never-ending, including washing vehicles (parked outside) every week. I’ve found that my car will “go green” in as little as two weeks during the winter rains *(akin to the five-day beard growth that just looks ugly). There was a guy down the street who let his broken-down car sit in his driveway for five years. Before he had it towed away, it had several inches of moss all over the car, including wild grasses a foot high or more that took root in various places.
You can get a big tube of Moss-B-Gone (I forgot the actual name, but it’s granules in a big cylindrical tube, maybe two feet long and four inches in diameter) at a home improvement store for 5 bucks or so. I just sprinkled the granules along the ridge line a day before rain was predicted, and let the next rain dissolve and spread them for me. Cleared my mild moss problem right up. Maybe not a good idea if you have plants you care about near the downspout, though.
Here you go: Moss Out.
Be sure to get the zinc kind for the roof because the one for lawns is iron and will stain.