well,
you should have removed them. Once they have been removed, and the shingles
get hot on the roof, that asphalt strip melts into the shingle it is
touching making for a much stronger bond.
Oh well.

wrote in message
oups.com...
That was the bizarre part - there were no instructions. Googled and
lots of instructions for shingling, silence on the tape - I assumed if
it had to be removed they would point that out, but kind of hard to do
once they're down!!
I figure very few homeowners nowadays do there own shingling, so why
bother with instructions, although there is plenty of space. The pros
would know.

Left them on, finished the job in a morning.