He swore it was just “character,” right up until he had to replace half his shingles after a windstorm.
Seen that happen more than once. I manage a few older properties and the “let it be” approach always seems to backfire, especially in damp climates. I’ve tried the copper strips too—honestly, they help but don’t expect miracles. Have you noticed if certain sides of your roof get it worse? North-facing slopes on my buildings are always the trouble spots. I’m curious if anyone’s had luck with those zinc strips instead, or is it just more of the same?
North-facing slopes on my buildings are always the trouble spots.
Same here—my north side is basically a magnet for that greenish-black gunk. I tried zinc strips last fall, and honestly, they seem about as effective as copper for me. Maybe a little less staining? Hard to say. I get what you mean about “let it be” not working out... I thought I could ignore it, but after one wet winter, it looked like my roof was growing a beard.
I thought I could ignore it, but after one wet winter, it looked like my roof was growing a beard.
That’s exactly how mine looked after last spring—like some kind of mossy chia pet experiment gone wrong. I get the temptation to just let nature do its thing, but on the north side, it’s like the algae throws a party every time it rains.
I’ve tried both zinc and copper too. Copper definitely left more streaks for me, but neither was a magic bullet. The strips helped slow things down, but didn’t stop the gunk from coming back after a couple months. Maybe it’s our climate (I’m in the PNW), but I feel like anything short of regular cleaning is just delaying the inevitable.
Here’s where I probably sound like a broken record: I started looking into “green” roof options mostly out of frustration with all the chemical washes and strip methods. Ended up testing out some algae-resistant shingles on my shed as a trial run. They’re pricier up front, but honestly, two years in and there’s barely any discoloration—plus no runoff issues into my veggie beds. Not saying they’re perfect or cheap, but for anyone already thinking about re-roofing, it might be worth considering.
Has anyone else tried those newer algae-resistant shingles? Or maybe even gone with something totally different like metal or clay tile to avoid this mess? I’m curious if folks have seen long-term results that actually hold up, especially in damp climates. Sometimes I wonder if we’re all fighting a losing battle with these north-facing slopes...
I’m in the Midwest and tried those algae-resistant shingles on my garage roof about three years ago. They’ve held up way better than the regular ones on the house, but I still get a little green creeping in along the gutters. Not perfect, but definitely less hassle than scrubbing every spring. If I ever redo the main roof, I’ll probably go that route, even with the extra cost.
Interesting to hear you’re seeing better results with the algae-resistant shingles. I’ve noticed the same—those copper or zinc granules really do slow down the growth, though like you said, the gutters and north-facing edges still get a bit of green. In my case, it’s usually where water lingers or debris builds up. The upfront cost is higher, but factoring in less frequent cleaning and longer shingle life, it’s probably worth it over time. If you ever do switch the main roof, you might want to look into adding a metal strip along the ridge too... that can help even more with runoff and algae control.