First, insulation does nothing to prevent freezing in the long term.
All it does is slow that rate at which heat is lost from the pipe. In
time the water in the pipe will freeze just as hard as if there were no
insulation.

Heat tape will prevent freezing so long as there is electricity
available to power the heat tape. If power fails you're still a
candidate for frozen pipes.

I have an application at one of my homes where I need to run well water
very near the surface because of ledge for about 200 feet. I also have
a 36" frost depth to deal with and frequent power outages. I did
extensive testing of various materials and selected polybutylene pipe.
It performed very well at temperatures to -30F when filled with water at
100 psi for in excess of 100 cycles. I also tested at 150 F in a
similar manner and had no failures.

Based on my tests I installed the pipe in 1992 and it is still
functioning today.

A lot of people will tell you of the problems that the industry has had
with polybutylene but in my experience the problems were all the result
of poor technique on the part of the installers. I installed quite a
bit of it, being very careful, in a harsh environment and have never had
a failure.

RB

ozark wrote:
Hi,
I am in the process of remodeling an older home. The existing water
supply lines need to be replaced. The house has an uninsulated
crawlspace where the pipes are run.
I am looking for the "right" way to do this. I need to decide if I
should use PCVC pipes with foam insulation or copper with heat tape.
It is my understanding that the plastic is less likely to burst if
frozen and it is a lot cheaper and easier to work with so I'm leaning
in that direction. The house is located in Missouri where winters
aren't too bad, but we still get below Zero ocasionally. There are no
building codes in the area. Any plumbers care to give their opinion?

Thanks

Ozark