I’ve wondered about the modular trays too—seems like they’d be easier to deal with if you ever need to check for leaks, but I get what you mean about water sneaking underneath. I had a friend try a single-layer coating on their flat roof, and it actually made pooling worse because it slowed down evaporation after storms. Have you tried any of those so-called “breathable” coatings? Curious if that helps with the Midwest humidity or just adds another layer of hassle.
Tried one of those “breathable” coatings on a customer’s warehouse a couple summers back. Honestly, it didn’t make much difference with our crazy Midwest humidity—water still hung around after any decent rain. The idea sounded good, but it mostly just added another maintenance step. I’m with you on the modular trays being easier for leak checks, but I’ve seen water sneak under them and rot out decking too. Sometimes feels like picking the lesser evil, especially with flat roofs.
Yeah, I hear you on the coatings. Tried something similar on my garage roof—supposed to “let moisture out” but all it did was trap musty smells and make the surface weirdly slick. Midwest humidity just laughs at those claims. Flat roofs are always a gamble... sometimes I wonder if we’re just delaying the inevitable repairs.
Midwest humidity just laughs at those claims. Flat roofs are always a gamble...
Honestly, I think the coatings game is mostly marketing unless you’re using something specifically designed for your climate and roof type. I switched to a green roof system (sedum mats) on my flat garage roof—sounds wild, but it’s actually kept temps down and moisture issues way less dramatic. Not saying it’s perfect, but at least the plants don’t trap that musty smell like some of those “breathable” coatings did. Midwest weather still wins sometimes, though...
at least the plants don’t trap that musty smell like some of those “breathable” coatings did.
That’s exactly what happened to me with a so-called “breathable” elastomeric coating. Looked great for about a month, then the summer humidity hit and my garage started smelling like an old gym bag. I swear it was worse than before I coated it. Midwest weather just finds the tiniest flaw and turns it into a science experiment.
I haven’t tried a green roof, but I did end up just going back to regular old rolled roofing. Not glamorous, but at least I know what to expect when it rains sideways. The coatings always seemed like a band-aid on a bullet wound for flat roofs around here. Maybe if you’ve got perfect drainage and zero shade, but that’s not my reality.
Still, I do miss the idea of having something up there besides puddles and mildew... sedum mats sound pretty cool, honestly.