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Frost Line

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Harvey Ramer
Harvey Ramer Member Posts: 2,239
Just talked to a guy that was digging today. He said the ground is frozen 3' deep. That is quite unusual for South Central PA. We are having an overwhelming amount of frozen pipe calls. Tomorrow I'll attempt my luck at thawing a couple underground supplies. Using a Steam Jenny with an 1/8" tube and some kind of a rocket tip. It shoots the majority of the steam backwards giving the tube thrust so it kind of self feeds. We'll see....

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  • icesailor
    icesailor Member Posts: 7,265
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    Be sure that it isn't Poly pipe!!. Bad things can happen.
  • Tom_133
    Tom_133 Member Posts: 888
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    Harvey,

    I hear you with the frost, locally in Vt because the mains are under the roads and the roads stay plowed (no insulation) the frost is freezing mains all over the place (5'+). We need one more -20 day to do us in!!

    Tough winter.
    Tom
    Montpelier Vt
  • Harvey Ramer
    Harvey Ramer Member Posts: 2,239
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    Tom said:

    Harvey,

    I hear you with the frost, locally in Vt because the mains are under the roads and the roads stay plowed (no insulation) the frost is freezing mains all over the place (5'+). We need one more -20 day to do us in!!

    Tough winter.

    It sure is a tough winter! A busy one I might add.
    If you guys freeze much deeper, you'll end up with a permafrost. Wonder how they run their mains in Alaska? Weezbo?
  • FranklinD
    FranklinD Member Posts: 399
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    Ugh. Local utility guy told me that under the roads where they're digging right now it's frozen down to 6' in some spots. They don't have issues with mains freezing but the old cast iron keeps cracking due to the horrible ground heaving.

    We bury most of ours at 8 feet here. Replacing a lateral line to a house or a curb stop is a pain...most are around 6-7 feet down (Superior, WI/Duluth, MN)
    Ford Master Technician, "Tinkerer of Terror"
    Police & Fire Equipment Lead Mechanic, NW WI
    Lover of Old Homes & Gravity Hot Water Systems
  • Steve_210
    Steve_210 Member Posts: 646
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    Watermain depth requirements from what I can remember
    London England 2'6"
    New York City 4'
    I believe in Canada it can be up to 7'
  • icesailor
    icesailor Member Posts: 7,265
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    And in the shade, it might be enough without snow cover.
  • Robert O'Connor_12
    Robert O'Connor_12 Member Posts: 728
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    Burial depth is 42" inches in NJ. As cold as it's been, I have not heard of a services freezing here yet.
  • Tom_133
    Tom_133 Member Posts: 888
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    Here is a rough one:

    Just had a customer call and tell me his apt line is froze but the main house (mansion over a million bucks) is ok. I asked how the line is run and he said one main from the road and then it tees under the driveway to the apt and he thinks it's been frozen a couple weeks. There are two kickers here, one its under the electric radiant in the driveway and so it can be warmed but if it's broken they have to dig up the radiant and shut off the water to his mansion. If it thaws with no break he's ok, but if he allows to stay frozen it will most likely break and this spring he will get dirt in from the break in the mansion, a flood in the driveway and will need someone to come out dig it and fix it. Oh the woe's of the rich!!
    Tom
    Montpelier Vt
  • kcopp
    kcopp Member Posts: 4,443
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    I have a customer here in the seacoast of NH who had his 2" main freeze to his home. City water. Steel . 4 1/2' under ground. 38' long. This place is literally on the water.
  • icesailor
    icesailor Member Posts: 7,265
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    @Tom:

    It is highly unlikely (and I mean VERY highly unlikely) that the water service will break if frozen in the ground. The service freezes from the outside in. The ground freezes solid and transfers the heat/cold to the pipe, with the middle of the pipe being last to freeze. If the driveway is snow melted protected, and it is on, it is highly unlikely that it is frozen under the driveway if the snow melt is working. If the connection to the garage/cottage is under the driveway, and runs to the garage, if the service utilities come up out of the ground, close to the (inside) outside foundation wall, it will more likely freeze as it comes up into the building. Is there a curb stop next to the garage building? Does the curb stop operate? If it doesn't, the curb stop is frozen in the ground.

    Honestly, I've had a lot of experience with these types of situations. More than once, I was on my belly with both arms in a meter pit trying to turn something or thaw something, and someone stopped to see if I was alive. Once the cops. He was pissed that I wasn't dead or injured.

    As far as the main house, run water in the first sink as close to the service entrance as you can get. Turn on the cold water and let it run on your hand. If it gets so cold that it hurts your hand, the service is getting ready to freeze. The frost is around the service pipe. If it gets really cold, leave water running. There's enough heat energy to keep it from freezing. Turn it on wide open regularly. If you get green or colored water for a period and it clears up, it was freezing. That's the stuff coating the walls being scrubbed off by the ice.

    For what it is worth.
  • Tom_133
    Tom_133 Member Posts: 888
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    @Ice:

    Thanks for the info, I am hoping all will be well and hearing that makes me think it will be. Though I wouldn't mind operating a machine for a day or two as I move the line or repair it!!
    Tom
    Montpelier Vt
  • icesailor
    icesailor Member Posts: 7,265
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    You have no idea what it will do to a machine, trying to punch holes in frost. It rips the snots out of mini excavators.

    If you dig a trench 4' down for a water service, and you come to a building with a concrete floor, you punch a hole in the concrete to snake the pipe up through. You have to push the dirt down to someone outside digging in and under the footing. Then, when there's room, the outside person digs out the dirt and pushes the pipe through. The outside person shovels the dirt into the trench and tries to fill up the inside hole. There's never enough dirt inside to fill it up. If that spot is in shade or in shade most of the day, or on a North side, that/e where it freezes up. The last place to look. There's always extra dirt left over to get rid of. If there's 3' of frost, some of it runs under the building. If you have a thermometer gun, shoot the floor next to the foundation. If it is under 35 degrees and close to 32 degrees, there's frost close by.

    How do I know? If you own toys, you should use them to see how else they can help you. You will never know how helpful one of those can be. I used one to check for heat in my wife's leg after she had a knee replacement. My bionic wife. two knees and a hip. She uses one to check for heat in a horses hoof.
  • hot_rod
    hot_rod Member Posts: 22,266
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    under a roadway, it's the traffic over the lines that drives the frost down. Alongside the roadway under snow they are better protected from frost.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Weezbo
    Weezbo Member Posts: 6,232
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    Howdy Harvey Ramer, :)
    Wanna buy some future Sub tropical swamp..er beach front?
    Sounds like the cold is making itself known in the USA this year.
    Once again we use supply and return , Insulated ,4' min burial on these 80 K copper lines ,when they run into the house ,we make some fancy loop with a take off to the new lead free aub and the double check and meter ...If the Main is over 100 feet away we add an additional Stainless steel re-circulator into the loop. we do not discuss prices here on the wall buh what i just said is well over 2 thousand dollars for insulation , parts ,pipe ,permits , inspections ... with out excavation , plumbing and believe it or not meter grounding and assorted misc hardware....underground , our pipes do not touch and are about 3 inches apart held there by blocks of blue foam every 4 to six feet or as warranted by the variations of the ditch.
    for every foot closer to the surface we must put another additional inch of insulation beneath above and on the sides of the pipe. and usually cover that with fill hose it down compact it and continue to back fill with gravel and compaction .. this is only allowed on residential property..where it goes into the street it comes off and returns on the main from pit orifices .... tapped and saddled to the main, aligned to flow , one scooping in ,the other directed against flow ( to create a differential pressure) for circulation.

    So, maybe you could spin in some insulated pex over ground for now , from the lateral in the main home ,with a circulator . till Spring... you may need an ice bucket or fire teeth on the hoe to dig right now,.. an excavators a lot faster though and more likely of getting it done the first time.
    We electrically "Buzz" the copper pipe laterals by breaking a union when water comes out of one side we close the valve and lash it all back up again if only the one line was frozen.

    I still have not been able to convince the city to use pex tubing..
    It certainly could be done and from all the underground tanks (water) installed
    if it is not on permafrost , pex seems to be fine . i think one pipe size larger would be a better deal on the supply side lateral , on water tanks you have to be careful the insulated tank is not sitting on frozen ground , that could end up freezing the pipe pick up tube in the tank (which is usually pvc)...any way Howdy.

    *~//: )


    Harvey Ramer
  • Tom_133
    Tom_133 Member Posts: 888
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    @Ice:

    Sorry meant this spring, should've wrote it.
    Tom
    Montpelier Vt
  • Harvey Ramer
    Harvey Ramer Member Posts: 2,239
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    Howdy to you Weezbo!

    I knew you had a way, I just didn't know what it was. I do now, and it'll be useful if I ever move to Alaska and start plumbing, :)

    It is interesting to me how things get done in different parts of the world.
  • SWEI
    SWEI Member Posts: 7,356
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    Interesting, so a kind of diverter tee loop off the main and up to the meter?
  • icesailor
    icesailor Member Posts: 7,265
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    There is a lot of frictional heat from car tires driving on a road. The more cats traveling, the more firction. Plus the radiated heat from the undercarriage. The first place in a road to that is where the car tires have driven. Then. it gets squishy in the middle, as it thaws and melts. Less traveled roads loose their snow last. The last snow to leave is the shaded snow.

    As far as frost, look at as the inverse of the "Lake Effect" where ice floats on top of the lake. And once the whole lake is covered with ice, the bottom of the lake is 39 degrees.

    Cold in a parking lot can be the OAT on the surface in shade. Ice on the lake will be the same as the OAT, but 32 degrees at the bottom of the ice plate, floating on the water. What decides the thickness of the water/ice is the amount of heating/cooling BTU's to effect either form of ice or water.

    Frost in the ground has lots of moisture in it. The depth of the frost is determined by the amount of heating BTU's to overcome the cooling BUT's of the cold. If the OAT in the parking lot, next to the frozen lake with 12" of ice is measured, the ice will be 10 degrees (OAT) at the top but will be 32 degrees at the bottom of the slab. If you dig a hole in the parking lot, the temperature of the ground will be well below 32 degrees, 12" down.

    Anther system crash caused by Heatinghelp.com. From yesterday. Sometimes its saved by HH.com, sometimes, not.

    PEX, PP AND PVC will freeze as fast as copper when buried underground. Even with insulation as freeze protection. It just freezes slower. Water flow through the pipes is what keeps it from freezing. Where I used to work, the water company has bleed offs at the ends of low use Mains that were subjected to freezing.