1) Built up with Gravel (called Tar & Gravel Roof)
2) Modified Bitumen (Rubberized asphalt with colored granules)
3) EPDM (a type of synthetic rubber)
4) TPO (Thermal plastic)
5) PVC (soft Poly Vinyl Chloride)
6) Metal Roofs
7) Shingle Roofs
All roofs are made to keep a roof from leaking while the water moves off the roof system. The above listed membranes do the job well. Call for questions and answers to which roofing system would be best for you.