How cold does it need to get before copper pipes burst?
I just started a fixer project in a small town (LaConner) near Seattle. The foundation had to be jacked, the crawl space cleaned out, the insulation removed, the leaky water tank hauled away, the service panel moved, and the electric baseboard heaters disconnected (in advance of installing a gas furnace). Now that everything’s been taken apart and there’s no heat, it’s going to snow. It’ll probably dip below freezing, but not by much. So, do I drain the pipes, leave the water running, or work on installing heat and/or insulation? Or will a slight freeze not affect anything?
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I've had short , slight frozen with no ill effects. One tho' was a hard , overnight and solid ice in a 3/4", and it burst.
Since then, I take NO chances below 15 degrees..I let it drip out of various openings, and keep a supply of spare pipe and sharkbites..and a few comp. fittings, and a few fittings and solder and flux..Just in case.
I'd venture to guess, where you are..if it does dip below 20..it won't stay that way for long, but I have been wrong before.
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations
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sphere, wouldn't the use of Pex allow a certain amount of freeze up without bursting?
yes frenchy.
Yes & no.
Pex is more pliable than copper, but if you freeze pex to a rigid state then it's weaker than copper.
I have some copper pipes outside, that supply watering points in the yard. A few times, our fickle weather has led to my failing to drain them in time. In each case, it was during the thaw that the pipes burst.
So, all you need is a significant freeze ... it doesn't matter whether the freeze is to +25 or -25.
Yea. They don't leak till it thaws..funny that?
No seriously, I get that, for some reason water is STILL not compressible even when frozen..and the coefficient is ...well
here.
http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/waterdens.html#c2Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations
They kill Prophets, for Profits.
I think you may have misunder stood my statement ....
I've been present, when a perfectly fine pipe split, with the sound of a gunshot, shaking the entire house. In every instance, this happened during the thaw part of the cycle ... and not during the freeze-up.
I've also had this happen with bottles of soda, left in the car too long. Freezing is fine; it's during the thaw that the glass breaks.
Laconner get's colder than Seattle ;-)
It's not really how cold it gets, but how long it stays below freezing.
Sunday to Tuesday morning it's supposed to stay below freezing.
If it was my job, I would shut the water off & blow out or shop vac the lines.
Type "L" copper burst before "M" does. "M" usually expands a few times before breaking.
If it's cold enough to freeze it's cold enough to burst your pipes regardless of what grade copper you use. Water is at max density at 4 degrees C above freezing, in it's liquid state. If the water temp drops to 0 degrees C the water essentially remains liquid for awhile until it gives up it's "heat of fusion" at which point it forms solid ice at 0 degrees C. Liquid water at 0 degrees C and solid ice at 0 degrees C have different internal heat, this internal heat energy is referred to as the "heat of fusion." During the process of changing from a liquid at 0 degree C and solid ice at 0 degree the water expands by about 7 % in volume. If water is close to freezing temps for any length of time, the process of going from liquid state to solid state and expanding in volume by 7 % volume can take place very quickly or somewhat slowly, depending on just how far below freezing the air temp is. Copper does stretch somewhat but if the volume of water confined is large enough, then the pipe or valve (brass or iron) will split.
In short, if it's cold enough to snow or leave a frost on the ground, it's cold enough to split your pipe (32 degrees F or 0 degrees C is freezing).
Do you gamble?
Take five mins to empty the pipes, use an airline to clear the low spots. You know its going to be a week or two before heat is on again. Anti freeze the toilets tank and bowl too.
Keep in mind that it will be 5-10 degrees warmer in the crawl than outside, even if not fully enclosed. Warmer still in an enclosed house.
I'll never forget the Christmas when I drove with my Dad and a brother to my sister's and when we rounded the bend in the park where her trailer was, the street was full of water and I said, "I pity the poor person whose pipes froze and did that!" only to find out it was in front of my sister's trailer and I in my wing tips shoe and Sunday best ended up helping her boyfriend fix the broken pipe! He had taken the fitting off the main supply to the trailer because the water had frozen and then he chipped the ice out! Needless to say, somewhere along the way of the chipping, he freed enough that the water suddenly burst through the remaining ice and then he was unable to put the fitting back on! Several pipes under the trailer had cracked with the ice too.