Shingle over shake roof life expectancy
I have a home built in '63 with shake roof installed over spaced slats. The location is Sacramento CA. Sometime later shingles were added over the shakes. In recent years a few shingles have been replaced after wind storms, etc. There has never been a leak. We have treated the exposed shingles with bleach to combat moss growing on the North slope. We are now attempting to sell the house and a roof inspector is indicating the roof is "mushy" in places. The suggestion is roof replacement for ~$10K+. Virtually every other neighboring home has replaced the roof--mostly with composition material. Should we request a second opinion?