My original shingle roof has lasted 24 years, problem free. Now, I am
planning to have a new roof installed (after tearing off the old) and I
am learning there is way more to this than meets the eye! One issue is
flashing around my brick chimney .

The current flashing is galvanized steel. There has been no leakage.
About 15 years ago I went up there and painted it because it showed
some unsightly rust. The paint job still looks good.

Most re-roofing bids I've received have included new chimney flashing
and I've never questioned that until I got the latest bid from a
reputable contractor. He told me that he would be glad to reflash the
chimney (for $450), but that it didn't need to be done. He said a good
galvanized flash job would last forever, if painted.

Further, he commented that the dormer up on the roof (75% of chimney is
inset in the dormer) was built around the chimney, and it would be
difficult to do as good a flashing job as the original effort. (He did
indicate that he could do a good job. It's just that he didn't think it
was necessary.)

I've done a fair amount of Google research on flashing. Many folks have
suggested replacing valley flashing when re-roofing, but I've found no
discussion on the pros and cons of reflashing a chimney versus keeping
the old, problem-free existing flashing. I get particularly concerned
when I read all the horror stories of flashing jobs gone bad.

All I want is a good job, and the piece of mind that comes from knowing
that the new roof and related work will last, and be problem-free. What
do you think?
Tom