Totally agree about polyiso and vapor barriers being lifesavers—been there, done that. One thing I'd add: don't skimp on edge details and flashing. Had a job once where everything was perfect except the edges weren't sealed right... spent days chasing phantom leaks before realizing water was sneaking in from the perimeter. Lesson learned, haha. Details matter big time, especially on mod-bit roofs.
Yeah, edge sealing is critical—learned that the hard way myself. Had a mod-bit roof done a few years back, and the contractor rushed the flashing around the parapet walls. Looked fine at first, but after a heavy rain, water started creeping in behind the insulation boards. Took forever to pinpoint the source because it traveled so far before showing up inside. Definitely worth taking the extra time to get those perimeter details right... saves headaches later.
I've seen similar issues myself, though in my case it wasn't the flashing but rather inadequate insulation thickness causing condensation buildup. Initially, I thought it was a leak too, since water stains appeared randomly on the ceiling. After some frustrating detective work, turned out the contractor skimped on insulation depth, and the temperature differential was causing moisture to condense inside the roof assembly. Had to redo the insulation entirely—expensive lesson learned.
Given your experience with perimeter detailing and edge sealing, I'm curious if you or anyone else here has experimented with tapered insulation systems under mod-bit roofing? I've read mixed reviews—some swear by it for drainage and preventing ponding, while others argue it's unnecessarily complicated and costly. My skepticism comes from seeing poorly executed tapered systems that ended up creating more pooling rather than less. Seems like proper installation is key, but then again, that's true for most roofing details.
Also, has anyone had experience using cover boards over insulation panels? I've heard they can significantly improve durability and puncture resistance, but I'm still weighing whether they're worth the added expense. Would appreciate hearing about any real-world experiences—good or bad—with these methods.
We had a similar issue with condensation... thought it was a leak too until we opened up the ceiling and realized the insulation was barely there. After redoing it, things improved dramatically. I've been wondering about cover boards myself—heard they help, but the cost makes me hesitate. Does anyone know if they're actually effective long-term, or is it more marketing hype than real improvement?
Cover boards aren't just hype, honestly. Had a similar hesitation myself, but after installing them on our modified bitumen roof, we noticed less wear and tear over time. Not cheap, but definitely worth considering if you're thinking long-term.
