On Tue, 06 Dec 2011 12:52:24 -0600, "Doug"
wrote:

On Tue, 6 Dec 2011 08:48:49 -0800, "Steve B" wrote:


wrote Since the new shingles are supposed to seal up
any existing leaks, who
cares if/where it is currently leaking?

Old shingles I have seen have the gravel sloughing off. There isn't much
for the new ones to stick to that's solid. And if there's a hole or a
missing shingle, what does it stick to?

Steve


Basically agree with what you said except here. You're right about
the sloughing but wrong about new sealing to old. New are nailed down
and are suppose to lay on top. Problem is that the old may not be too
flat so the new will not be flat neither. I can't remember now but I
think they use felt paper (tar paper) between old and new shingles.

Never seen tar paper between shingle layers.