During the phase change from liquid water to solid ice, the
water (ice) expands. It can easily crack the pipe. So that
when the weather warms up, the drain trap leaks.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"HeyBub" wrote in message
...

I don't understand. How can freezing of water in a p-trap
present a
significant problem?