My husband is up on the roof right now putting insulation on the pipes that were missing it. That's right, they are on the roof. My sill, who owned this house before us, needed to have it re-piped and went with the cheapest option which was putting the pipes on the roof. Our roof is almost flat so it works ok except that our water is steaming hot in the summer and frigid in the winter. Most of the pipes already had insulation (we did that when we moved in), but there was a section that needed some work not too long ago. The insulation was taken off and never replaced. Luckily, there doesn't seem to be any damage from the freeze last night. Hopefully the insulation on it now will prevent them from freezing tonight and in the future!