Now is the time to do it right. By right, I mean the complete assembly. Do a complete tear off, install plywood, install synthetic underlayment, in your environment install high temperature peel and stick along the eave(three feet above the inside of the exterior wall) as well as the valleys. Install a balanced ventilation at the soffit and ridge. I also recommend that you buy a roof from a manufacturer that is part of the Metal Roof Alliance. All us agree to promote quality metal and paint systems.
thanks for considering a metal roof. Let us know if you have any other questions.
Dick Bus
2017-07-11 15:51:03.000000
Have a house with cedar shakes and then a hard asbestos type shingle over the shakes. Some installers said they will go over the existing roof and then other installers want to do a complete tear off and new plywood. Confused as to what is right way??