eHoefler wrote:
You should run the w pattern. The purpose of the w, is to have a melted channel from the leading to the low point. Running parallel in the valley does not make a path into the valley. You may have a clear path in the valley, but you would have no path to the valley.
True, but the objective is to prevent ice-damming so melting snow back two feet on either side of the valley is not needed.
I do some heat cable installation for ice damming and there is not a whole lot of need to heat an entire valley unless the valley is a source of water intrusion. I typically just make a double run up the valley until it is past the overhang area (usually 3' or so). If I am using the cables on all the overhangs, the valley run can be part of the overall cable run. BTW, don't forget the downspouts. Depending on ambient temps, the downspouts may freeze solid if not heated. That is typical in Winter up here.
