1) It would be very difficult to apply. You use roof jacks under the
shingles on Steep roofs. No place to fasten them with the rolled roofing.
2) and most important. There is too much unfastened span of material. The
large unfastened area will sag and tear as gravity pulls it down from the
narrow nail area along the top. Even walking on it on a steep roof will
cause it to tear from the nails.
"Goedjn" wrote in message
...
Why is it that asphalt roll roofing never seems to be used for
steeply pitched roofs?

It doesn't appear as if it's contra-inducated by the
manufacturer.

--Goedjn