best for low pitch roofs
Coupla things in reply:
First, thanks for the feedback I got from you both. It helps.
2. I measured the pitch, roughly, from the ground, using simple things like a horizontal measurement I could take from the ground combined with measuring on the ground the height of the number of pieces of horizontal siding it appeared to take to go up to the peak of the low pitch part of my roof, etc. Using that rough technique, I believe the pitch of the low part is steeper than 2:12 but less than 3:12. Definitely not as steep as 4:12.
3. MJW, you remind me of a factor I failed to mention. Our lot IS surrounded entirely by large oak trees. Our entire house is almost always in nearly full shade. We know from the appearance of the roof that it does have trouble drying; moss growing under low hanging branches, etc. So that factor could influence our choice of product, I guess; I'm just not sure what it suggests I should consider!
4. Fox, your comments about how the one roofer I spoke of discussed the issue of guarantee are spot on. In fact, now that I think about what he said, I do think that in fact he was saying exactly what you said: the mfg's guarantees depend on what's used in what circumstances, and that's all he was summarizing to me. I do NOT believe he was raising a red flag with respect to his own work, and I appreciate your insight on that issue!
So, all that having been said, IS a conventional shingle roof using ice and water protection all the way to the peak on the low pitch side and just 3' up on the two parts of the roof that are 4:12 or steeper going to be sufficient?