After a 10-year interruption, we're re-roofing the last side of our
(hip) roof. The other three sides are done with asphalt shingles over
felt paper. Now, my brother the roofer says he uses "Tri-flex 300"
underlayment, instead of felt. His reason for that seem to be that it
doesn't tear, so (a) it's easier to put on, and (b) it seals better
around nail holes. The only reason we have not to do it is that we
already have the felt on, and it's not clear that the Tri-flex will
If anyone has any experience with this, I'd appreciate hearing of it.
The roof pitch is ~40 deg, and we get snow in winter, sometimes quite