rhagfo wrote:
Flapper wrote:
wa8yxm wrote:
Finally, The reason freezing damages pipes is because they are FULL of water which expands when it solidifies (turns to ice) in this it is unique, only substance on earth that does that. However if the pipe is say half full of air,, no damage can be done, since air, unlike ice, compresses very easily (ice too can be compressed but it is not done easily) (This last is proven by ice core samples at the polar ice cap by the way, the bottom is denser than the top, indicating compression).
Close, but not quite right on the theory - the ice expands and compresses the air, and it is the extreme air pressure that cracks the pipes. :h That's why they are always split some point after the ice, and why the plumber's advice to always leave a tap open in extreme weather. Of course, if your system allows two plugs of ice to form, then the piping in between is at risk!
I agree that if you hear gurgling, then the water is not out of the system. Even with my large tank compressor, I have to do the pressurize, rest, repeat thing several times before I stop getting anything out of the faucets.
Boy I hope that is an attempt at Sarcasm!! :B
The water would need to really expand to compress the air in the lines enough to crack the pipes!!
X2
All you need to do is bleed your brakes wrong, and you'll understand fast why you hope it's sarcasm.
But I see the fellow is from MN where it gets extremely cold, so I'll add some flesh to the bone cause I'm sure he's seen a lot of broken copper pipes/fittings over the years.
He is correct on stating that the pipe does not have to be full of water to break. The assumption is the frozen water will keep expanding into the air gap thus no damage, which is not true. Look at how boulders break. Water gets into a crack and freezes to the point the boulder is forced apart and will break. The water had the ability to expand upward in the crack which would be less resistance, but that is not how nature works. Ice expands in all directions, just ask a MN ice fisherman if he ever had ice crack under him, the answer will be "of course." If ice only expanded into the least resistance then the ice would have expanded up into the air.
