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Melting Ice in real life

  1. Jan 9, 2009 #1

    I live in the northeast, well known for its heavy snowfall in the winter. Where I live, for the past few days, it has been raining heavily during the daytime and stopped at night. This has collected in various ducts and pipes meant to remove the water from the roof. At night, when the temperature drops below 32ºF or 0ºC, this still water freezes, blocking the pipe.

    One pipe in question is in the shape of an uppercase letter "L", where the short branch is perpendicular to the surface of the earth and the long branch is parallel to the ground, but underneath it by a few inches.

    I suspect that it is frozen along the pipe for a few inches under the ground. The whole vertical section is a solid block of ice. This is causing a backup along the pipe.

    It is supposed to snow tonight. How can i clear this pipe before then, and keep it cleared throughout the night?

    I know that salt melts ice by lowering the temperature at which salt water freezes. But this is a very slow process and to melt about a solid gallon of ice will not happen before tonight. It also, most definitely, will not be able to keep the pipe clear and flowing throughout the night.

    Is there any way to clear the pipe quickly and then have a slow release or timed release of salt into the pipe using stuff found regularly in a home?

  2. jcsd
  3. Jan 9, 2009 #2


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    The problem with slat is that it has to dissolve in the water to have any effect, it also only lowers the freezing point a little bit. So it's really only useful if the ice is only a little bit below freezing. They don't bother putting it on roads in Alaska.

    The only thing I could think of is to add some hot water with salt and hope this thaws enough of the ice to let the salt dissolve into it. You might have to make a hole in the pipe above ground level to let the water drain if the underground part is still frozen.
  4. Jan 9, 2009 #3


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    Fro quickly thawing a frozen pipe, it's hard to beat a small butane torch. We used to use that on the northeast corner of my former residence (the windward corner) when the plumbing would freeze.

    As for keeping it free overnight, perhaps a screen with some salt on it placed like a drain-cap over the open end of the pipe. As water flows over the screen, salt will slowly disolve and flow into the moving water in the pipe. If your temperatures are not getting very far below freezing, it should be enough.
  5. Jan 9, 2009 #4
    The problem with the butane torch is that this is not a metal pipe. It's a PVC pipe underground, but high enough that the ground doesn't shelter it from the cold. Basically, it's easily dug up, but I don't know how that could help.
  6. Jan 9, 2009 #5


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    The underground pipe is difficult. Even if you put hot water and salt in it's not going to do any good unless it can melt the existing ice.
    To clear the downpipe and stop the ice backing up into the gutters you might have to drill a drainhole near the ground at the bottom of the down piece.
    Then if you can put hot water/salt down it from the top, or the sun comes out and melts it at least it will drain.
  7. Jan 9, 2009 #6


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    You can also buy electric heat-strip cords that can be coiled around pipes.
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