On May 5, 7:18 am, "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 ?

Yes there is a strip of adhesive on the underneath to helps to hold
down the shingles. Look closely at the shingle and you will see it.
You don't do anything since the adhesive is self bonding with the
shingle underneath. Once the shingles are installed the sun warms the
up enough to melt the glue. It is not a real strong glue but it does
hold down the edge of the shingle which the nails cannot do.

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

Bonds to the shingle only. There is not wood underneath the shingle
anyway only a layer of tar paper. Of course the first coarse bonds to
the paper.

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

One sunny day above freezing would do it, really. This strip of
adhesive is nothing for the homeowner or installer to be concerned
with or worried about. Yes, it is there, but it sticks to the other
shingles on it's own and does not affect or inhibit the installation
or repair of the roof in any way.

The time you really notice it is when tearing it off. Then you will
see that the shingles are not only nailed down but they are stuck to
each other as well. This actually is helpful since you can sometimes
tear off large sections of shingles if they are stuck together well.