I’ve actually seen moss do more than just hold moisture—it can sneak under the edge of a boot and start lifting it, especially if the seal’s already a bit tired. That’s when you get leaks and rot, not just cosmetic stuff.
That’s exactly what happened on my old shed roof—moss crept under the rubber boot, and by the time I noticed, water had already started seeping in around the vent. The deck was soft in spots, and I ended up replacing a few boards. I get the argument for swapping boots regularly, but I’ve always wondered if there’s a more sustainable approach. Rubber boots don’t last long in our climate (Pacific Northwest, lots of rain), and tossing them every few years feels wasteful.
I tried a recycled rubber boot with an integrated moss barrier last year. It’s holding up so far, but I’m skeptical about longevity. Metal flashings are tempting, but like you said, they’re not perfect either—especially with salt air from the coast. Has anyone experimented with green roof layers or living moss barriers to keep moisture away from the vulnerable spots? It seems like there should be a way to use moss as an asset rather than just fighting it all the time...
I’ve seen a few folks try to use moss as a sort of “natural” barrier, but in practice it just doesn’t cooperate. On one job near Astoria, the moss actually accelerated the breakdown of the boot—kept it damp all year, and the rubber cracked faster than usual. Metal flashings do last longer, but like you said, salt air is brutal. I’ve had better luck with silicone boots—they’re pricier up front, but they seem to handle both UV and constant moisture better than standard rubber. Still not perfect, but less waste over time. Green roof layers are interesting, but I’d worry about trapping even more moisture around penetrations unless everything’s sealed up tight.
That’s been my experience too—moss just seems to make things worse, especially in damp coastal spots. I’ve had a few roofs where the moss looked nice at first, but then the boots started splitting way sooner than expected. Silicone boots are definitely pricier, but I agree, they seem to hold up better in the long run. Have you noticed any issues with them getting brittle after a few years, or do they stay flexible? I’m always a bit wary about green roof layers for exactly the reason you mentioned... moisture just loves to find its way in.
I’ve had pretty mixed results with silicone boots, honestly. On one hand, they do seem to outlast the cheap rubber ones, especially in wet climates—my place is just a few blocks from the coast, so I get hammered with rain and salt air. But I have noticed on a couple installs that after maybe 5-6 years, the silicone starts to chalk up and lose some flexibility, especially on the south-facing slopes where the sun just bakes everything.
I totally get the hesitation with green roof layers. I tried a “living” roof mat once, thinking it’d help with insulation and storm runoff, but it just turned into a soggy moss farm and made every penetration a headache. The boots on that section failed way faster than on my regular shingle roof.
Have you ever tried those metal retrofit boots? I’ve seen a few folks around here swap over to them, especially after storm damage, but I’m not sure if they’re worth the extra hassle or if they just end up leaking somewhere else down the line.
Metal retrofit boots are a mixed bag. They’re definitely tougher than rubber or silicone, especially in coastal areas where UV and salt eat up everything else. I’ve seen them hold up 10+ years with barely any maintenance, but only if they’re installed right—flashing tucked under the shingles, screws sealed, all that. If someone just slaps them over the old boot and calls it a day, you’ll get leaks around the fasteners or at the base eventually.
One thing to watch for: metal boots can be a pain if your roof isn’t standard pitch or if you’ve got odd vent sizes. I’ve run into a few where the fit was off and it actually made things worse. Also, if you’re dealing with a green roof or anything that holds moisture, metal can rust out faster unless it’s stainless or really well coated.
If you’re already swapping boots every few years, it might be worth the hassle to try metal, but only if you or your roofer are willing to do the install by the book. Otherwise, you’re just trading one headache for another.
