Yeah, those copper mesh strips can help, especially if you’re not up for running a full ridge cap. Have you noticed any staining around the mesh over time? I’ve seen it leave streaks on lighter shingles, but maybe that’s just me. North sides really are a pain—seems like no matter what you do, they stay damp. Ever tried just letting it ride and seeing if it gets worse, or do you always treat it?
Yeah, I’ve definitely seen those greenish streaks show up under the copper mesh, especially on my neighbor’s pale gray shingles. Mine are a darker brown, so it’s not as obvious, but I still notice a bit if I’m looking for it. I tried skipping treatment one year just to see what would happen—north side got pretty gnarly, honestly. Ended up with a patchy mess and had to scrub it down anyway. Seems like it’s just one of those things you can’t ignore for too long, at least around here where the trees keep everything damp.
Seems like it’s just one of those things you can’t ignore for too long, at least around here where the trees keep everything damp.
- Totally get this. My place is basically in a grove, so shade + moisture = algae party.
- Tried the copper strips too, but yeah, those streaks are real on lighter shingles. On my old tan roof, it looked like someone spilled green tea up there.
- Skipped a year once thinking the “self-cleaning” claim might actually mean something. Nope. North-facing side got that fuzzy green beard and I was up there with a scrub brush feeling pretty dumb.
- What’s worked for me: cheap garden sprayer + diluted bleach mix (careful with plants below). Quick spray every spring, 10 min job, keeps the worst away. Not perfect, but less work than scrubbing.
- Heard zinc strips can help too, but haven’t tried them yet. Copper’s easier to find at the hardware store here.
- Honestly, I think in our climate you’re just picking your battles. Either you’re up there once a year, or you’re dealing with the mess later. At least it’s a good excuse to check the gutters...
That “self-cleaning” label gets me every time—wishful thinking, right? I’ve seen a lot of folks go the bleach route, but I always wonder about long-term shingle wear. Zinc strips can work, but you’re right, they’re not as easy to track down. One thing I tell people: watch those gutters after spraying, since runoff can stain or corrode metal if it sits too long. And yeah, nothing like an algae beard to remind you spring’s here...
That “self-cleaning” label gets me every time—wishful thinking, right?
Yeah, I hear you on that. I’ve seen those “self-cleaning” claims on shingle packaging and always have to laugh a little. Maybe if you live somewhere with zero trees and no humidity, but around here (southeast), it’s more like “self-growing” when it comes to algae.
I’ve tried the bleach thing a couple times for clients, but honestly, I’m not a fan. It works fast, but I’ve seen what it does to older shingles—makes them brittle over time, especially if you get a little heavy-handed or don’t rinse well. Plus, like you said, the runoff is no joke. Had a neighbor who ended up with streaky gutters and some weird spots on his landscaping after he went wild with the sprayer.
Zinc strips are solid in theory. I put them on my own roof about five years back—took some hunting at the local supply place to find the right size. They do help slow down the algae, but you’re right, they’re not magic either. You still get some streaks below vents and chimneys where water runs more.
One trick I picked up from an old-timer: copper wire. He’d run a length of bare copper just under the ridge cap. Not as pretty as zinc strips, but copper’s even more effective at killing algae. Only downside is it can stain lighter shingles greenish if you get a lot of rain.
And yeah, those gutters... If you’re spraying anything up there—bleach or one of those “roof cleaner” mixes—flush your gutters right after. Otherwise you’ll be dealing with pitting or rust spots before long.
Funny thing is, after all these years patching storm damage and cleaning up after hurricanes, it’s still the little stuff like algae that drives folks nuts every spring. At least it’s not hail holes or missing tabs this time around...
