kevwalsh wrote:In reality, many of us have roofs that have, well, less than
ideal
designs. Mine is 50 years old, rather flimsy, cape-cod style. Many
existing roofs are very hard to insulate and ventilate properly. Due
to cost, historic building restriction, aesthetics, and many other
reasons, many of us just have to find a way to keep our houses
leak-free, despite a poorly designed roof system. It is always an
uphill battle, of course.

Tarpaper is next to useless when it comes to ice and water buildup.
I'd personally love some ice-and-water peel and stick on our roof.
When we redo, we'll put some down. Nails will leak sooner than
adhesive. You really want something that is water proof, not just
something that uses gravity to direct water down the roof. Our house,
for instance, can get ice dams (if we are not very attentive, and let
things go) about 10" to 14" thick, which leads to a pool of water as
much as several feet back from the edge. This will submerge the nailed
edge of whatever you have down, and leak. The sticky tape will do a
better job, hopefully.

I'm betting "cost" is the major restriction to a proper roof, especially to the
builder. Historic building restrictions? Would that apply to the attic
insulation, too? I'd love an historic roof, especially cedar shingles over
scabboards. Of course, it doesn't get very close to ice dam situations here in
Southern AZ, at my altitude. How do you attend to your ice dams to keep 'em
down? I've chopped at them, but it's dicey. Too easy to damage the shingles.
Tom
Work at your leisure!