Brite Tek is a thermoplastic material as opposed to a thermoset material like a fiberglass roof. Fiberglass along with a thermoset resin means once it is cross linked (cured) it will not be affected by adding more heat until it surpasses the glass transition temperature which is about 350 F for epoxy resins. Thermoplastic materials can be reformed multiple when heat is applied. Having said all that, 7mm of TPO (Thermoplastic Polyolefin) is a little over 1/4 inch which is very thick for a roofing membrane and would be very durable. I think my rubber EPDM roof is about 1/8 thick. I am not sure how thick a FG roof is, maybe someone one here knows.