Funny you mention the heavy-duty waterproof coatings on low-slope roofs—I've always been a bit skeptical about those too, especially around here where humidity is basically a year-round sport. I get why folks want to slap on something that promises “no more leaks ever,” but does anyone really believe that’s the end of the story? Every time I see one of those roofs, I start poking around for signs of trapped moisture. Nine times out of ten, there’s at least a little bit of staining or that telltale musty smell hiding somewhere.
I’ve had a couple clients who went all-in on those coatings after a bad storm season, thinking it would solve their problems for good. Fast forward a year and they’re calling me back because their ceiling is sweating in July and they can’t figure out why. Turns out, the roof’s basically wearing a raincoat with no way to dry off underneath. It makes me wonder if we’re just trading one problem (leaks) for another (rot and mold).
One thing I’m still trying to wrap my head around: why do people skip right over the ventilation step? Is it just not as flashy as putting on a shiny new coating? Or maybe it’s because you can’t see airflow, so it doesn’t feel like “real” work got done? I’ve lost count of how many times I’ve found soffit vents stuffed with insulation or painted shut like you mentioned. Sometimes I feel like half my job is just pointing at blocked vents and asking, “Hey, what do you think happens when air can’t get through here?”
And insulation—don’t even get me started. It’s wild how often people pile it up thinking more is always better, not realizing they’re suffocating their own attic space. Maybe we need an attic version of Goldilocks: not too much, not too little... just enough to keep things breathing.
Anyway, totally agree that coatings aren’t evil by themselves. But if the basics aren’t right first, you might as well be putting lipstick on a pig. Curious if anyone’s actually had long-term luck with those thick waterproof coatings in muggy areas without running into condensation issues... or is that just wishful thinking?
- Ran into this exact thing last summer. We did a coating job on a flat roof for a neighbor—looked great at first, but by August, the inside was starting to smell funky.
- Pulled back some ceiling tiles and, sure enough, there was moisture trapped between the coating and the old roof. No leaks, but definitely not dry either.
- The owner had blocked off a bunch of vents “to keep bugs out,” which just made it worse.
- I get why people love those coatings—easy fix, looks clean, and you can brag about it to your friends. But if the roof can’t breathe, it’s just asking for trouble in humid places like ours.
- Ventilation seems boring compared to shiny new stuff, but honestly, it’s what keeps everything from turning into a science experiment up there.
- I’ve seen a couple of jobs where the coating held up okay, but only when the attic was vented right and insulation wasn’t piled up everywhere.
- Not saying coatings are bad, just that they’re not magic. If you skip the basics, you’ll probably end up with a different headache down the road.
I’ve always wondered—do folks realize how much those blocked vents can mess things up? I get wanting to keep bugs out, but trapping moisture is way worse. Ever tried those mesh vent covers? They let air flow but keep critters out. Curious if anyone’s had luck with those.
Ever tried those mesh vent covers? They let air flow but keep critters out.
Yeah, I’ve seen those mesh covers work pretty well, especially on older homes where bugs and birds love to sneak in. Just gotta make sure the mesh isn’t too fine or it’ll clog up fast with dust and stuff—then you’re back to square one with blocked vents. Moisture buildup is no joke under a roof... I’ve had to crawl into some gnarly attics because someone thought stuffing vents was a good idea. Mesh seems like a decent middle ground if you keep an eye on it.
- Mesh covers are a solid idea, but yeah, if you go too fine it’s basically a dust trap.
- I’ve seen folks use screen door mesh—seems to balance airflow and critter control pretty well.
- Agree about moisture—blocked vents are a nightmare. Had mold in my attic once because insulation was jammed right up against the soffit vents.
- Curious if anyone’s tried those “breathable” roof coatings? I hear some can actually trap moisture if your venting isn’t dialed in... seems like it could make things worse instead of better.