- Q.What’s the best way
to insulate plumbing supply lines in an exterior 2x6
wall?
A.Master plumber Rex
Cauldwell responds: This is like a trick
question. The answer is, you don’t. My
rule is that if it is cold enough to have the pipes
insulated from freezing, then you
shouldn’t put the pipes in the outside
wall. By insulating them, all you do is keep the
heat from inside the house from getting to the
pipes. Insulation just slows down the freezing
process, it doesn’t prevent it.
Stay out of the exterior wall and go through the
floor. For those of you who ignore my advice, you
have to use heat tape and closed-cell foam pipe
insulation.