Putting a metal roof over asphalt shingles

[Bill Gaiche]

We had our medal roof installed 9 years ago. Its put down on the shingles. It doing just fine. The roofer had been installing metal this way for a long time up to this point. He said that there is a lot of untrue stories about the old shingles rubbing holes in the metal and moisture build up. But if anyone is unsure and can afford it then put what ever makes you feel more compfortable with under the metal. bg

[Kcwoodbutcher]

A little clarification as to why I don't want to spend a lot of money putting this roof on. I picked up about 200 square of this metal roofing from an insurance company for a mere $600. It was supposedly hail damaged but I couldn't find one dimple in the whole mess. Basically it's in great shape, a little oxidation, but that's it.  The holes are already there so I will have to use them. It's even the right color. If I can get 15 to 20 years out of it I will be happy.