while i agree, option 1 is the 'best'. but if your roof isnt leaking now,
if you factor in price vs how long it will last, you may find option 2 may
be viable.

i am also assuming that there is only one layer of roof already (i.e. hasnt
already been reshingled over another layer). if there are multiple layers
already, tear it down.

lastly, if you want the longest lasting roof, i'd go with a metal roof.

randy

This summer we plan to replace our 24-year-old shingled roof with
long-lasting dimensional shingles. The old shingles are still in pretty
good shape and the house has had no ice damming problems.

Contractors are pushing two schools of thought for the old roof.
1. Tear it off and put down ice and water shield before putting on new
roof.
2. Shingle over the old roof and utilize the old flashing.

Which process would you recommend for the longest-lasting roof?

Thanks for your thoughts.

Tom
Milwaukee, WI