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!
For an occurrence as rare as that, you can protect yourself by just
letting a faucet in the house drip a little., That will turn the water
over enough to keep it from freezing for a short time.
You could try a recording thermometer under the home to see how cold
it really gets.
Technically I'd say 32F but my experience says more like 28 to 30F
where I am but the other question is how long it really has to be at
this temperature before you have to worry. In other words, if it's
32F just for an hour, you probably don't have to worry.
I think in Texas, the weatherman says like 4 to 5 hours at that temp
but I'm guessing a bit. I'll let others chime in on this latter
question. But my experience does say 28 to 30F regardless. In
Texas, the old timers will tell you to let the water drip to make the
water move but nowadays, they say don't do that... probably because we
have too many people now :( .
I second the motion to just leave the tap at a slow trickle on really
cold nights. If you're more paranoid than that, they sell "heat tape"
expressly for this purpose. It is thermostatically controlled so will
only use energy when it's needed. You probably wouldn't need to wrap
it tightly at all (don't, you'll burn it out) in that moderate
climate. Just wrap a loose helix of the heat tape around the pipe,
put an inch or two of fiberglass around that, and wrap it all with
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.
It will break the first time it freezes, though it has to get really
cold. One strategy with silcocks is to leave them open (and shut off
the water inside).
It's my understanding that it's a lot more forgiving. I have PEX in
the house we just moved out of. One run to a silcock is in an
uninsulated garage wall. No problems with freezing, though the house
is in East Alabama. Again, one advantage of PE is that it's used with
a manifold so one can just shut off the lines that are likely to
freeze (and leave the tap at other end open).
I left a hose connected one year, in our Vermont house. Frostless
silcocks don't work worth a damn if you leave the hose connected. ;-(
Fortunately, I was home in the morning and heard the water running.
On 1/8/2013 5:52 PM, email@example.com wrote:
My pipes had frozen repeatedly as builder had pipes to laundry room go
through unheated space. I had been working on keeping them unfrozen
before they broke.
I would expect PEX to be better as it should contract if expanded
whereas copper would just stretch.
I had a plumber reroute my pipes but sometimes the PVC drain will freeze
but has never broken. Must recover like PEX.
A rule of thumb might be to look at the plants by your house. Do
they ever freeze? I think tomatoes are particularly susceptible to
There should be some residual heat from the ground to keep the temps
below your house above freezing.
The wrap around fiberglass insulation is cheap. It might be worth it
for your peace of mind to wrap the incoming water pipes. I wouldn't
bother with heat tape.
I lived in Green Valley, AZ used a faucet cover such as: Frost King
2-1/4 in. Sock Faucet Cover, available in Home Depot, Lowes, Ace.
Never a problem over six winters.
For a permanent fix, replace outside faucets with integral freeze
plugs faucet types.
Quick fix (we have very old property along the gulf coast) is one of those
temperature operated recirculation pumps used for houses that have a long
run from the hot water heater to the delivery point.
We set up one to work at the minimum setting + a simple a timer. All in
all I think we have $50 bucks invested (that was 10 years back).
This may work without the hot water heater being on but I don't see the
justification given the circumstances you outline.
One thing not mentioned are drain lines. There may be a low spot that can
freeze as well
Someone I know recently passed along these articles about frozen pipes that
I thought were interesting:
"Preventing Frozen Pipes"
"If Your Pipes Freeze"
I am not sure that I completely agree with or believe what one article says
about the pipes breaking from the line being a closed system, rather than
necessarily breaking at fittings etc. I thought that I remember cast iron
radiator heating pipes breaking at the fittings more than anywhere else.
But still, the articles seemed to be somewhat useful in my opinion.
Geometry has an effect that may help in explaining that as well as
perhaps the fittings are just the weaker link--a long run has a better
chance of absorbing the expansion along it as opposed to a short section
w/ elbows on both ends. When the ice forms at the elbow it effectively
stops any additional longitudinal movement/expansion and any additional
expansion has to go outwards...
I don't know what your lines are made of. Lines on top of the ground are
going to be more influenced by ground temperature than air. But you
probably have wind. I don't think black holding tanks are insulated, but
would little in them if attached to drain.
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