A Colorado Homeowner wrote and asked:
We are reroofing our mountain cabin. There is a large portion of the roof that is virtually flat and has, historically, been the source of much leakage. It was covered a year ago by new asphalt. We are now planning to install a metal roof. Is metal a good choice for this low pitch section? Someone told us if we leave that section asphalt, it allows easier access to the rest of the roof, because it’s easier to walk on, but we want to make sure it’s protected.
Also, is it better to leave existing roofing materials down and install the metal directly on top, or better to rip off the old before installing the new? How does that affect the noise?
You can leave the existing in place but you should cover it with a layer of underlayment or something as a slip sheet between the two.
The only type of metal roof that will be suitable for this low pitch will be a mechanically seamed standing seam.
Walking on the metal roof will not be an issue and you should not notice any objectionable noise transfer.