water line freeze damage

[KenK]

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

[gfretwell]

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.

[Doug]

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 :( .

[krw]

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 tape.

[Frank]

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.

[chaniarts]

it only takes once. damhikt.

[krw]

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.

[Frank]

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.

[krw]

It all depends on how hard the freezes are. Like you, I'd expect the effects on copper to be cumulative but they can let go the first freeze if it's hard enough.

Within some bounds, sure. If the water is trapped, though, it will put a lot of stress on even PEX.

I wouldn't think it would be much better than copper, though may not freeze as easily (copper is a pretty good conductor ;-).

[Dean Hoffman]

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 freezing. 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.

[shellyf_DELETE_]

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.

[hrhofmann]

Why not just enclose the area under your mobile home? It would work and it would look much nicer also.

[NotMe]

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

[TomR]

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.

[dpb]

On 1/9/2013 12:35 PM, TomR wrote: ...

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...

--

[gregz]

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.

Greg