"Robert11" wrote
Hello:

Concerning roof shingles.

I understand that there is some kind of "adhesive," or perhaps just plain
tar, on the undersides
of the normal 3-Tab style.

The nailing in of these provides the major adherence to the wood
underlayment of course, but how important is the
adhesive bonding ? How does it actually function ?

Is this bonding to the wood, or is it to the underneath shingle (only) ?

How many weeks, generally, of hot weather does it takes this bonding to
be effective ?

Bob,

In respect to the "Normal 3-tab", the adhesive on the underside is there to
hold the cellophane or paper to the shingle. This is placed there so the
tar strip doesn't stick to other shingles when packaged. You will see most
all manufacturers now print on the cellophane/paper "Do Not Remove".