Helps keep water from getting through the roof.

--
Christopher A. Young
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..


"Micheal C. Jordan" wrote in
message ...

Shingles (standard three tab type) have felt (tar paper?)
installed on the
roof first, and then the shingles are installed. What is the
function of
the felt? I understand there are 2 types of felt, perforated
and
non-perforated. Is perforated felt for vapour movement? What
happens if
the felt is not installed?