I’ve got a few buildings with those low-pitch sections and valleys, and you’re right—those spots are always the worst for moss and gunk. Even with zinc strips at the ridge, I still end up sending someone up there every spring to brush out the corners. The strips seem to help a bit, but it’s never a total fix, especially under big maples or firs. I’ve noticed that if the roof’s got a shallow pitch, water just doesn’t move fast enough to carry the zinc down, so you get those green patches hanging on for dear life.
One thing I’ve run into: sometimes owners want to add more strips halfway down, thinking it’ll “double up” like you said, but honestly, I haven’t seen much difference except for some weird streaking. I’m not convinced it’s worth the extra cost or hassle. On one property, we tried copper strips instead, just as an experiment. Didn’t see a huge improvement, but the moss did seem a little less stubborn in the shadiest spots. Hard to say if it was the copper or just a drier year.
I do worry about folks getting too aggressive with cleaning, though. Had a tenant try to “help” by pressure washing a patch of moss off, and it tore up a bunch of granules. Ended up with a leak the next winter. Now I just tell everyone—soft brush only, and don’t mess with it if you’re not comfortable up there.
Anyone else dealing with insurance companies getting picky about moss? I had one inspector flag a roof just for a bit of green in the valley, even though the shingles were fine. Seems like they’re looking for any excuse these days.
I actually think those extra strips halfway down can help in some cases, especially on really wide or super shady roofs. It’s not a magic fix, but I’ve seen less moss right below them compared to spots without any metal. The streaking looks weird, yeah, but if the owner’s more worried about moss than looks, it might be worth it. Still, nothing beats just keeping branches away and gutters clear—metal or not, that makes the biggest difference for us.
Still, nothing beats just keeping branches away and gutters clear—metal or not, that makes the biggest difference for us.
Couldn’t agree more with this. I see a lot of folks get caught up in the “magic bullet” solutions for moss, but honestly, regular maintenance is what really keeps things in check. Those zinc or copper strips do help, especially on north-facing or tree-shaded roofs, but they’re not a cure-all. I’ve inspected plenty of places where the strips worked for a couple feet below, then you get a hard line and the rest of the roof is still green and fuzzy.
The streaking from the metal can look odd, but I guess it’s a trade-off. Some people care more about curb appeal, others just want to avoid scraping moss every spring. I’ve even seen folks try to hide the streaks by painting the strips, but then you lose the whole point since the metal needs to be exposed to work.
One thing I’d add—sometimes those strips get installed too late, after moss has already taken hold. If you don’t clean off what’s there first, the new strip won’t do much. And if your roof’s got a really low pitch or poor sun exposure, even the best metal won’t keep up if you’ve got piles of needles and leaves sitting up there all winter.
I’m in the PNW, so moss is just a fact of life here. My own place is surrounded by firs, and I swear I spend more time on a ladder than I do inside some weekends. Keeping gutters clear is huge—not just for moss, but for preventing ice dams and leaks too. I’ve seen water back up under shingles just because a downspout was clogged with pine cones.
If anyone’s thinking about adding strips, just make sure you’re not covering up existing issues. And don’t forget to check for loose shingles or popped nails while you’re up there. Sometimes the “little stuff” ends up being what causes the big headaches after a rough winter.
That’s pretty much how it goes at my place, too—no fancy tricks, just a lot of time up the ladder. I’ll add one thing I learned the hard way: if you’re clearing gutters, double-check the downspouts for blockages. I thought I had everything cleaned out last fall, but turns out a wad of maple seeds was jammed in one elbow. Didn’t notice until water started dripping inside the porch after a heavy rain... Fun times.
I get why people want to try those metal strips or chemical treatments, but around here (also PNW), nothing beats actually getting debris off the roof. My old neighbor tried those spray-on moss killers and it just made a patchy mess—plus, the dead moss stuck around longer than the live stuff. For me, it’s been all about trimming back branches and getting up there every couple months when it’s dry enough.
One thing I don’t see mentioned much: check your vent boots and flashing while you’re up there. Mine cracked after a cold snap and I probably wouldn’t have caught it if I wasn’t already poking around for moss. Little leaks can turn into big repairs fast if you miss them.
- I’m with you on the “no magic fix” thing. Tried those zinc strips a few years back—didn’t do much except stain the shingles and annoy me.
- Gutters are always a pain, but it’s the downspouts that get me every time. Last spring, I thought I was in the clear, then found a bird’s nest wedged in the bottom elbow. Water everywhere.
- Moss is relentless here (I’m just north of Seattle). I’ve given up on chemicals—just scrape and sweep when it’s dry enough to not break my neck.
- Good call on vent boots and flashing. I missed a cracked boot once and ended up with a slow leak into the attic insulation. Didn’t spot it until I noticed a weird smell months later... not fun.
Curious—anyone actually had luck with those gutter guards or screens? I keep hearing mixed things, especially with all the fir needles around here. Worth it, or just another maintenance headache?