Yeah, rigid foam boards are definitely a solid choice. I had a similar issue with a flat roof on one of our buildings a few years back. Initially, we went with spray foam because the contractor swore by it, but after a couple winters, we started noticing moisture buildup and even some mold spots. Ended up having to rip it all out—total pain. Switched to rigid foam with proper venting and haven't had an issue since. Being able to actually see and inspect the insulation makes a huge difference...lesson learned the hard way.
Yeah, rigid foam definitely has its perks, especially for flat roofs. One thing I'd add—make sure you're sealing the seams really well with tape or adhesive. Learned that the hard way myself...tiny gaps can cause big headaches later.
"tiny gaps can cause big headaches later."
Totally agree with this. I've seen some projects where folks skipped sealing the seams properly, and moisture ended up trapped underneath—talk about a mess. Curious though, has anyone here tried combining rigid foam with a green roof setup? I've heard mixed things about compatibility and drainage issues, but it seems like it could be a solid combo if done right...
- Yep, tiny gaps = expensive oops later. Learned that the hard way after a storm peeled back some poorly sealed flashing...fun times.
- Green roofs + rigid foam can def work, but drainage is key. Seen it done right a few times, but also seen soggy disasters.
- Curious if anyone's tried adding drainage mats or geo-textiles between foam and green layers to help with moisture control? Seems like it might help avoid headaches later.
Drainage mats can definitely help—saw a place last year that used them under the green layer, and it seemed to hold up pretty well after some heavy rains. But honestly, I've also seen setups where they skipped mats entirely and just relied on gravel and proper slope...worked fine too. Makes me wonder if mats are always worth the extra cost and hassle, or if good slope and gravel alone might do the trick?
