Me wrote:
The back porch leaks water during a particularly heavy rain storm. New
shingles were put on about a year ago by a professional roofer and it
didn't leak until I hammered up ceiling boards to the inside of the
porch just recently.

On inspection, there is a thick bead of black caulking along the top of
the flashing where it lies against the brick of the house but it must
have microscopic cracks in it to cause so many leaks.

If I took a heat gun and ran it along the bead of caulking along the top
of the flashing, would it melt enough to seal any cracks? Or is it
necessary to remove the old caulking first then apply new?

Any more ideas, particularly better ones?

You probably have some sort of warranty on the work, or at the very
least the interest of a reputable contractor in correcting defects, so
call the contractor. Just be respectful, clearly describe the problem,
and see if he will take a look. If he is even halfway decent, he has an
interest in making sure his work was done properly and the customer is
happy.

I read somewhere....on the newsgroup?....that the majority of roofing
jobs require callbacks. We had severe problems with installation of a
$47K job on our condo...everything went well on correcting the situation
until someone on the condo board got ****y about it. Had two major
reworks for badly nailed shingles....our particular shingles were a poor
choice for our particular roof. In the long run, we ended up better off
when the hurricanes came through in '05...contractor had gone over the
whole thing to put adhesive under the tabs and that kept them on in the
near-hurricane force winds.