11/01   How long are roofs supposed to last? My friend is buying a home w/
        a 15 yr old roof and the inspector said it's got about 3 years to go
        (it currently has no issues). I was wondering if that's about average
        for a given roof (in SF). If it's not, it could be because it's a
        shitty roof or the contractor just being overly conservative.
        \_ That's about right for a cedar shake roof: they dry out, start
           curling and cracking and that's all, folks.  Asphalt shingles will
           last a little longer; if it's asphalt that's still within the realm
           of possibility, it probably just wasn't a great quality roof to
           begin with.  --dbushong
        \_ Depends totally on the roofing material.  20 years is not unusual
           for a cheap roof.  -tom
           \_ And in the early 90s there was a lot of cheap work being done
              in the sf market.  Prices were really low and people didn't want
              to invest huge amounts into real estate.
              \_ The roof is made out of iron and slate.
                 \_ A well-made slate roof should last 50+ years.
                    A crappily-made roof, your guess is as good as mine.  -tom
                    \_ I agree. A slate roof should last forever. Are you
                       sure it is really slate and not some slate-like tile?
                       \_ it was damaged by the troll-like creature
                          living under the stone and iron roof.
                          http://csua.org/u/hcp