Can you avoid tearing off your old asphalt shingle roof by putting a steel roof over it? Maybe. Most codes now allow no more than two layers of roofing before requiring a complete tear-off. So, if ...

Q: I was inspecting my asphalt-shingle roof the other day. At the top of the roof where the peak is, I noticed some defects. My shingles are only 6 years old, so I was shocked to see deterioration.