Depends on where you live. Snow starts to melt, run part way down the roof, then refreezes at the edge. Water builds up behind this "dam" and runs under the shingles into the building. In Wisconsin, I'd go with the highest pitch I could afford. Lots of homes were built with 4/12 pitches around here in the 50's and 60's, but they sometimes suffer from those ice dams. Now many are built with 8/12 or more. 12/12 is nice if you can afford it and if someone else is going to shingle it. A high pitch also gives yo overhead storage.
Pete Stanaitis
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