The minimum pitch for an asphalt roof for Asphalt shingles is 2/12 or more as long as you use at least one layer of ice and water shield and one layer of synthethic felt under the architectural shingl ... read more
Both of the previous are great ideas. Also consider, if it is an older valve, that the main does not close completely, for a variety of possible reasons. We see that alot in older homes. You can confi ... read more