TPO
Posted: Wed Dec 20, 2017 4:30 pmLooking for a quick short spec for TPO. I've always used EPDM, but the FL contractor wants TPO. Would be nice to be generic, no more than 4 or 5 pages.
Dwight:
We use TPO or PVC single ply roofing on most of our projects and it is manufactured by Carlisle and Johns Manville among others. This roof is white which meets cool roof requirements. Just be sure to wear snow goggles when you inspect the roof. Its very easy to detail and install.
We work with waterproofing/envelope consultants on most of our projects and they recommend 60 mil thickness. They don't see any real advantage of going with 90 mil.
If the roof membrane is installed over rigid insulation, we specify 1/2" gypsum roof board, (DensDeck Prime) over the foam to provide rigidity to the substrate.
Our consultants prefer the more expensive PVC over TPO roofing because of some evidence of long term failures in TPO roofs. We always specify PVC, but will generally agree to TPO as long as the client understands the trade-off.
I have attached our typical specification section. Here is the note we use on our roof plans:
CLASS A PVC SINGLE PLY ROOFING OVER 1/2" DENSDECK PRIME ROOF BOARD OVER 3" MINIMUM RIGID INSULATION OVER STRUCTURAL METAL DECKING.
We don't have any experience with the product in colder climates, so there may be some variations required.
We have been specifying single ply roofing on our project for the past 15 years without any incidents.