Brent, it depends a lot upon your exact situation. As long as it is not a code violation and as long as there are no existing signs of a weight issue or rotten lumber / leaks on the roof, I feel that a lay-over can be safely done with many types of metal roofing. I always call for a layer of underlayment over the old shingles.
Todd Miller
2012-05-21 14:39:59.000000
We are getting quotes for a new metal roof. Do you recommend tearing off the old asphalt shingle roof?
Brent Kuykendall
2012-05-21 14:32:30.000000
+1
Most manufacturers do allow for it. All will require some sort of slip layer or underlayment.
