attics are made to vent so its not a good place for pipes in the first place.
but insulate to piss out of em. Heat tape is good also. An electric blanket for the pipes.
Though the big problem is just that its an attic, crawl spaces under a house don't seem any better but they are sealed and keep a better constant temp.
Which Im guessing you don't have crawl spaces down there? why they put the pipes in the attic?
Better then cement, next door theirs are like that, pipes were layed out then burried in cement, sure stops burst but hell fixing cloggs.
Though for really cold days we have vent holes in the heating ducts that can be opened so some of the heat is blown under the house but its not an issue unless its constantly below 0.
