Ok I'll play
So I'm late to the table so maybe I missed it but regardless of covering selection the cover-boards have gone a long way in preventing single ply failures due to collapsed iso. It's hard to beat the redundancy of any BUR......and I do miss the smell of asphalt or heating my sandwich on the tubes...but you can hardly pull into a parking lot with a kettle in tow and not expect the building to be evacuated. Besides the only bur roofers are old roofers. We agreed not to burn down any buildings with torch applied systems and our insurance carrier agreed not to raise our rates...as much... do you all have people in your area that call them rubber roofs? As for the single plys way too many issues with TPO including the solar loading from reflected heat. Have you ever picked up any piece of epdm laying around and noticed it's always wet underneath? However they'd be choice #2. I'd go with the PVC over a coverboard with proper design for R-vaule. Why - 1. ease of application. 2. nice to work on when it's 90 out 3. proven history. 4. welded seams proven to be better than glue or tape
