On 1/8/2013 11:53 AM, KenK wrote:
I live in far SW AZ where it rarely goes below 35 F or so. Rarely once or
twice in a winter it gets down to 28 or 30 F. Obviously we don't normally
insulate water lines or otherwise protect them from the cold. They are
exposed to the air under my mobile home. I have a wrapping of insulation
around the pipe at the well water pump and where exposed to the wind
elsewhere away from the mobile where they are easy to get at.

How cold does it have to get to cause the lines to break from freezing?
Anyone know? When should I start worrying? In 30+ years no water a few
times but no damage I am aware of. But still ... I'm a worry-wart!

TIA



I think it is the repeated freezing and thawing that breaks copper
pipes. Water expands when it freezes and expands the pipe. Done
repeatedly the pipe reaches its limit and breaks.

Might be interesting to know how PEX behaves.

I had a pipe break years ago while Mom and I were out shopping,
Good thing the kids were home and shut off the water as it would have
been a real mess. As your main water line, usually in use, you're
probably OK but leaving a trickle of water on when it's freezing outside
is a good idea.