My 1960s-vintage home has a hip roof--no gable to vent and built with no ridge vent. The roof has a 4/12 pitch. It has ample soffit vents and eight slant-back vents spaced out near the ridge line. This works fine in the summer and most of the time in the winter. However, when a heavy snow buries the vents, I'll get ice dams if I don't get up on the roof and shovel out the vents.
We'll be installing new shingles this summer, and I'd like to solve the roof-venting problem at the same time. I've found three possible solutions so far. They're listed below, starting with the most expensive. Can anyone suggest other solutions or comment on the likely effectiveness of the ones I list?
Most expensive: One or two cupola vents.