Is there any reference on the internet about temperatures and durations that
are required to freeze pipes?
Every year I get neurotic when they start having frost advisories about my
cottage. I know it takes hours to freeze ice cubes at 0 degrees, so it
obviously takes more than a few hours at 30 degrees to freeze pipes; but
some actual data would be nice.
It is a big chore to shut off the water, and then I am without water until
I'll be biting my nails this winter as well. I recently bought a new
construction summer home. I asked the builder when I was 'looking' if I
could drain the pipes and winterize it without many problems? And he
said 'no problem, I will show you when you are ready to leave for the
Well, of course he never did 'show' me and sent one of his flunkies by
with a CYA form that says I should keep the house on 60 all winter and
shut the water off etc. etc to ....." keep the studs and sheetrock from
freezing and causing all kinds of problems not covered under your
I've never heard of sheetrock freezing and causing a problem and 'studs'
????, I see new construction all the time left out in all kinds of
weather. This sounds like he would rather not get involved in advising
me how to winterize and he would rather BS to avoid it...Thoughts?
Its pretty easy to have a whole house drain at the incomming point,
then open all faucets to drain, drain water heater and just pour in
antifreeze in all traps, I do this often when I leave in only 5 minutes,
install a few 1/4 turn ball valves. Some Heat trace wire on the
incomming pipe through the wall keeps the supply from freezing. Keeping
a house 60f is a waste of money if you are not there. Will your basement
even freeze, I put in an extra large heat vent facing my pipes and open
it when I leave and reduce upstairs registers.
Other posts have good comments. If you can't or don't want to handle it
yourself then have a plumber do it--at least for the first time. If the
house is left unoccupied and unheated for (I think) 30 days and something
happens you might have an issue with the insurance company. If you're in an
a location where below 30 is not a frequent occurrence then why not leave
your thermostat at 50 deg or so and have complete peace of mind.
Well, not having any heat is a good reason to not leave the thermostat at
I know how to winterize the cottage, having done it 10 times. The issue is
when is it necessary to do it.
Will a low temperature of 30 overnight freeze anything. 25? 20?
Seems like a common enough problem that there ought to be some information
available on it.
I've asked this sort of question of plumbers a couple times (once during a
prolonged mid-winter power outage; once when discussing frozen heating pipes),
and both times they said that wind is a big factor, too.
My frozen heating pipe problem occured on the north side of my house, on a windy
So the reason I think you're not getting a firm answer is that it depends on a
lot of factors. How exposed are your pipes; how much insulation? What is the
exposure of your house? How much wind do you get. From what direction mostly?
I'd either drain the house the first time there's a projected overnight temp of,
say, 25 degrees (based on what the plumber I called told me during that
prolonged power outage) and be done with it 'till spring, or keep it to 50
degrees all the time. Because, otherwise, it'd always be on the back of my mind
" are my cabin pipes freezing; are my cabin pipes freezing", and life's too
short to go worrying about that sort of stuff IMO.
Is there anyone you know in that neck of the woods? What are their experiences?
Well, the answer to that is, obviously, yes. Now. is that "anything" a
plumbing line in a protected location and is "freeze" solid enough to
actually do damage--of course not--for one night. Now, what are the
daytime temperatures, where is the pipe, how long a run is it, is it
hot/cold water, is it in sunlight or shade, is ...???
There _is_ information available--water (pure water at atmospheric
pressure, that is) freezes at 32F, the coefficient of expansion owing
to the phase transition is known, the rupture strength of piping can be
estimated (although for old galvanized, for example, the existence of
corrosion weak points is problematical), estimates can be made for what
heat transfer coefficients/rates would be applicable based on geometry,
wind/air speed, etc., from which one could estimate how long it would
take for any given piece of pipe to freeze given a temperature profile.
Obviously, with so many variables, it is essentially impossible to
provide any conjecture that would be of any use to your specific
situation sight unseen.
As I noted previously, I'd not worry about the first occasional frost
at all. But, as critical as the low temperature is what are the daily
high temperatures (and daily temperature profieles) and what
temperature does the house achieve during the day? If it's 25F at
night but warming up to 70F pretty quickly during the day, obviously
that's a _WHOLE_ lot different than 25F at night w/ daily highs in the
low 40s, say, and cloudy and damp and windy. To reiterate yet again,
there are far too many variables and unknowns to provide much
quantitative information. All I can say is it will require getting
below freezing at the location of the pipes for a minimum of several
hours for there to be any significant chance of any damage. What it
will take for your cottage to reach that is anybody's guess, yours
surely should be far better than any of ours.
Seems like if it's such a big deal to winterize and you want to avoid
that until the last possible moment the thing to do would be to either
make some simplifications to the process by modifications to the system
or add some safeguards such as heat tape, insulation, whatever seems
required given whatever it is you have...
If it just falls to 30 overnight no you wont freeze,
I have a phone dialer Freeze Alarm that will call me if temps drop low
indiicating a heat failure. We don`t know your Zone , ground temp lows,
building, basement, etc etc etc so to answer you is impossible to know,
Put in thermoneter that records low temp
You didn't answer the question of what kind of temperatures you might
Yeah, ice cubes take a long time because the water is 60 degrees to
start with. If it is already at 35 it doesn't take long.
Why is it a big chore to turn it off? Are you including blowing out
If you don't expect the temperatures to get below 30 you probably can
get by without that. Just to be safe turn off the water and open a
faucet. You might have to get a line fixed but the cottage won't be
If you expect temperatures to get to 30 and stay there for a day or more
I sure would drain the lines too.
First, any "reference" would have to be specific to some particular
configuration and so would be difficult at best to be generalized to a
specific location. I'd not expect to find much that would be directly
In general, until it gets well below 20F for an extended period unless
a dwelling is completely unheated and there are openly exposed lines
the likelihood of a freeze hard enough to actual do damage is quite
low. The obvious is to have any exterior pipes like in a crawl space
at least insulated or heat-tape wrapped and have the space itself well
closed off to minimize drafts, etc. After that, remember that the hot
water supply pipes will freeze relatively more solid than the cold
lines owing to the tendency of the water heater to outgas the dissolved
oxygen. (Some say the hot water lines freeze "faster" than the cold,
but it's not so much how long it takes that's the problem but the lack
of expansion volume that causes the rupture in the hot water lines
before cold water lines.)
If one is going to be away for a significant time period it may not be
practical, but for short periods, one expedient is to simply leave a
couple of taps on those lines which are most exposed dripping so there
is expansion room--it's the lack of an expansion space for the volume
increase on the phase transition that is the cause of the real problem.
Obviously, for the entire winter this isn't practical.
Draining an entire system completely would be highly unlikely to be
necessary in any event--empty toilets so there aren't the valves to
freeze, obviously, open the taps so there isn't a closed system and
deal with the actual supply line that can't be drained or
pressure-relieved and you're good to go.
For the fall until actually closing the house, not knowing what the
place looks like or any more about how cold for how long it's hard to
speculate further, but I'd be quite surprised about having a problem
until it was well below freezing and remained that way for several days
unless it is bare pipe directly exposed.
BTW, shorter runs of smaller diameter tend to be more problematic than
longer runs as well as the hot water lines vis a vis the cold simply
because of the geometry between elbows is a shorter column for
expansion and the smaller lines have less latent heat capacity...
The big factors here are how cold it gets and how exposed the pipes in
question are. And how exposed is going to vary a lot depending on
construction, wind speed/direction, etc. If it got down to a low of
30 overnight for a few hours and the most exposure is just an outside
sillcock that comes out of the wall, I wouldn't be worried.
Here at my house in NJ, I went away for a week in Jan. While I was
away, near the end of my trip, we had several days here where the temps
were down into the low teens at night, and only in the mid 20's during
the day. During that time, the furnace went out. For how long, I
don't know, but suspect it was for a couple days right before I
returned. The house is of frame construction, about 22 years old, with
a full basement. I had a electronic thermometer sitting on the counter
in the kitchen, which is at the south end. It recorded a low of 32.
The only problem was in the master bath at the north end of the house,
also on the first floor. There, the cold water supply line to the
bottom of the toilet, where it connects with a plastic nut had sprung a
leak. It wasn't even actually cracked. The supply line comes up from
the basement via an exterior wall.
So, obviously, it got colder in that end of the house. I was very
lucky, as the leak although a constant stream, was small and while I
had water on the floor and water on the basement floor as well, there
was no damage to the tile, etc.
But, the real issue in all this is if it gets cold enough in an area
with a house with no heat to be worried about, I'd winterize or make
arrangements to avoid having to make panic mode trips because very cold
weather is on the way.
Just winterized my place in Flagstaff last weekend for the first time
this season. Nighttime temps have started dipping down below freezing,
and not sure what the weather will be like before the next time we get
back. We usually get up there 5 or 6 times during the winter, and it
doesn't seem like a very big deal to winterize each time.
I usually budget about 1/2 hour, and it's not all downtime because I'm
doing other things at the same time. Usually goes something like this:
Turn off water heater (learned the hard way it's very important to do
this first), shut off the water at the street, hook compressor to
outside hose bib, open water heater drain and let the compressor blow
the water out. Usually this takes long enough that I can turn off the
furnace, close the propane, and load the car while waiting. When the
water heater's empty, go through the house blowing out the faucets and
toilets. Pour antifreeze in the drains and the toilets, put the
compressor back in the shed, and I'm ready to go.
Been doing that for 6 years now, only had 2 problems, both my fault.
One time, forgot to blow out the supply pipes to the washing machine
(outside on the rear deck), had a nice split in the copper pipe when I
turned the water back on. Other time, as I mentioned above, forgot to
turn off the water heater before winterizing, burned out both elements.
Kind of amused the plumber who came out to repair the water heater - it
had been installed with both access panels facing the side wall of a
kitchen cabinet base, about 2 inches away, only way to change the
elements was to bring out the Sawzall and cut a couple of holes in the
side of the cabinet base, patch them up later. Oh, and he had to drive
back to town (a 40 mile round trip) because he didn't have the right
element for our heater in his truck. These are the kind of lessons that
stick with you, I have never made either of those mistakes again.
After the first winter, I have gotten to the point where I don't think
it's a big deal to winterize. But, that's my cabin. Is there something
about yours that makes it more complicated?
The cottage is in upstate NY.
The pipes are 1/2" copper. The cottage is built on piers, so the plumbing
is all exposed to the elements; but being in deep woods, there is rarely
This time of year the highs are about 55 and the lows are 40, so the cottage
interior is usually about 47.
But last night there was a frost advisory, so there was a chance the
temperature would hit 32. Given the precision of the weather forecast, that
means there is a chance it would hit 30 for a few hours.
So my question is basically, if they forecast is for a low of 30, are my
exposed pipes likely to freeze?
If not, what overnight low temperature do I have to be concerned about?
I broke down and drained the pipes today, so it is not actually an issue for
this year; but I will go through the same thing next year. A couple years
ago I actually started to insulate the pipes and add heat tape, but then it
occured to me that if I had a leak, finding it and fixing it would be 10
times as hard; so I abandoned the project.
Doubtful that it would freeze to the point of doing damage. But if it
is going to be vacant for months there is no good reason to leave the
water turned on. The lines might break from some other reason. Just
turn it off. If draining the pipes is a lot of work, don't bother.
Friends moved into a new townhouse, or house, in Herndon VA, near
Dulles, and the builder had put a riser in the kitchen next to the
back door on the wrong side of the insulation. I don't know how cold
it got, or if they were out of town at all -- He's a college
professor, it wasn't sabbatical and I'm sure he was there for all but
at most 2 weeks -- but the first winter a pipe broke inside the wall.
Did some flooding but I don't remember how much. My friend wasn't
upset, but then he rarely is.
Precision implies repeatability. If you're relying on the weather
forecast remember that they only have to get it wrong one time to hurt
Looking at risk/reward, if temps dipped down to 28 degrees or so for a
couple or three hours, it's unlikely that you'd experience hard
freezing and burst pipes. The problem is you'll never know with any
certainty how low the temperature will actually drop. If you guess
wrong by a few degrees and you were hanging it out there by not
winterizing...well, those are the sort of learning experiences one
I've used lights of various sorts to add just enough heat to protect a
pipe or whatever from freezing. Have you thought about replacing the
copper pipe with PEX? Simple enough to do and you can easily run the
plumbing through the house in a more protected location. Here's an
interesting tidbit on PEX and freeze/thaw tolerance:
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