Clearing frozen sewer line

Discussion in 'Workshop and Home Improvement' started by TheJackRabbit, Jan 26, 2013.

  1. SInce we have had record cold here my line from the house to the septic tank has an ice block of about 15 feet, as measured from the tank and from the cleanout. The tank is ok. The block is in the center of the line which must have a flat spot in it since it was not buried deep and my 8,100 pound truck has been driving across it for years.

    So, how to clear 15 feet of ice from a Schedule 40 sewer line?
    Yesterday we built a fire which burned 10 hours. All that happened is the ice block got bigger. Last couple of days have warmed above freezing and water from snow melt has percolated into the ground. It may have even entered the sewer line which may have cracked.

    Clearly, this spring, I will have to dig it up and examine the line and make needed changes.. In the meantime, any ideas on how to clear 15 feet of ice? One problem is no hot water here. So, would an electric power snake cut through 15 feet of ice? I have seen them used on roots and solid waste. Do not know about ice. Anyone have experience with this?
  2. D'Animal

    D'Animal Rescuer of Beagle and Landcruisers Moderator

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    I'm no plumber

    but

    I would probably try and use heat tape. They used to sell it to put on the edge of your roof and in your gutter to keep the ice from freezing and tearing your gutters off. Wrap a few coils on the end of a length of it and shove the coils all the way to the blockage from the tank end. Plug it in adn let it work it's magic overnight. It is waterproof.
  3. That is an interesting idea which never occured to me. I prefer Frostex which is an electric resistance wire inside a woven wire exterior. Highly flexible. Heat tape, the original, might be hotter. Whatever is used will have to be advanced into the ice as it melts. It could be wrapped aroung a snake (the flat type) and shoved forward as needed.

    Thanks for a good suggestion.
  4. e9999

    e9999 You want to do what...? Moderator

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    wow, the joy of cold climates.... :eek:
  5. D'Animal

    D'Animal Rescuer of Beagle and Landcruisers Moderator

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    The we used the stuff on our house in Iowa. The first version I remember using was thin and small like x-mas tree lights. The next version a few years later was flat similar to what shrink tube looks like. The final version I installed looked like romex.


  6. Joe_E

    Joe_E

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    Man, that's a tough situation that's not easily and quickly remedied. 15' is alot of ice. I would suggest that you definately try to warm the ground up over the area or it will keep freezing. It would be great if you had access to the heat blankets used in construction industry to keep concrete from freezing.
    Let us know how you make out.
  7. I cannot keep fires burning as there is not enough wood.

    Concrete blankets are a possibility if I can find any here.

    A hot power washer or steam cleaner might work- attach a hose to the nozel and run it down the line cleanout to melt ice. Water will be displaced through the clean out.

    Temps have warmed to above freezing which might help although it will get cold again. Probably not as cold as it was (below zero).

    The line might just have to be dug up and replaced. It is not very deep- perhaps two feet. The tank is also shallow so the line cannot be made deeper. It looks like a soil berm will have to be placed over the line to improve insulation or wrapped with Frostex or heat tape. Then the line will have to be protected from compaction by vehicles. The line transects a gravel driveway.

    I was hoping a power snake might have an attachment to grind through ice. Does not sound like it, though.
  8. Weedhopper

    Weedhopper

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    How about a salt water slurry mix ? A LOT of salt.
  9. Septic tank specialists do not recommend salt or anti-freeze draining into septic tanks. It screws up the biologic process of digestion and creates a new problem. Perhaps that could work in connection with pumping out the tank. Also that would be very slow melt. It might help with further freezing should the weather turn cold again.

    I appreciate the thought.
  10. KLF

    KLF Frame waxer

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    As a licensed septic designer since 1986, I've designed and supervised many installations with very shallow plumbing, and my own line from house to tank is very shallow, maybe 12" of cover. I've never seen one freeze that has proper slope. Usually a frozen pipe is the result of a sag in the pipe, or in one case it was tree roots. The sag causes solids and sediment to build up due to settling, reducing the effective diameter. Then the water hits the frozen slug of solids and slowly clogs off the remaining opening.

    Even if you fix this clog, it's gonna happen again until you get the sag out of the pipe. My suggestion if possible, is to contact a local site contractor that is also a licensed installer, have them dig up the pipe now and fix it for good. Unless the ground is too frozen now...

    If the pipe is going under a driveway, it needs to be sleeved in cast iron to protect it, and the fill material in the trench needs to be highly compacted to keep it from settling again. Check the rules in your state, but for example in NH that pipe has a minimum slope of 2%, or 1/4" per foot.

    Do not use strong salt solution or anti-freeze to thaw it out, you'll ruin the anaerobic digestion process in the septic tank, which risks failing your leaching field.
  11. The slope and bedding of the pipe are likely the problem. I am sure the pipe is not in a sleeve and there is a low spot. The initial blockage, as measured with a snake from the tank and from the cleanout, is right under the tire track in the driveway.


    Proper installation is unheard of here. No one compacts CLEAN fill in the trench before laying the pipe. There are no inspections and General Contractors usually do the work themselves with the usual level of competence this area is known for- 9th grade education!

    The ground is frozen. But when the thaw occurs, I will be digging it up and redoing the job correctly. I was thinking of using a small diameter culvert for a sleeve. Do you think that will work?

    Since the thaw is several weeks away, I was hoping to clear the line with a hot power washer. Then cover the surface ground where the shallow line is with straw bales to insulate the ground some. Until the line is replaced with a sleeved pipe, no more cross traffic by trucks.

    Thanks for the info. Any thoughts on a temporary clearing of the blockage are appreciated.

  12. KLF

    KLF Frame waxer

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    A steam cleaner should work for getting the ice thawed out, but it is gonna be a messy nasty job. Keep in mind that anything you spray or shoot in the pipe from the house end has no escape, so it's gonna come flying back out towards you, into the basement. That sediment is gonna come out in chunks. Make sure you're wearing protective suit and a respirator, there's some bad bugs in that stuff, could make you very sick.

    A section of conduit could work as a sleeve, it needs to be rigid. Can you get concrete? CMP metal could also work if you can find it, it's getting scarce as plastic has taken over. I would try to fill the gap between with something like spray foam.

    Instead of hay bales, I would get a couple sheets of 2" XPS foam, lay that down with maybe some plywood on top. I sometimes call for this to be placed on top of septic tanks or pump chambers if there is low cover.
  13. Fortunately, the clean outs are outside.

    I was thinking of attaching a hot water hose to the endof the power washer wand to focus the stream down the line to where the blockage is. You are certainly right about the back flow and that is a good suggestion about a respirator.

    I was not referring to conduit as a sleeve for the new line but a culvert- 10 or 12 inch diameter. That is corregated galvinized steel which is used normally for vehicles across roadways which pass over surface water streams and ditches. It should work in this application as well.

    I am a long way from sources of building supply so I use what is on hand and that means hay and straw bales which do have a high insulation value. The bales could also be covered with plywood or corregated roofing metal sheets to keep them intact.
    The rigid foam with plywood is a better idea and if I can find some that would be a better solution.

    Too bad I am not in your service area. I'll bet you would do a better job than the the Yahoos in this area. This has been a consistent problem with all of the building trades- no pride in their trade or craft. Just do the easiest job and get out.
  14. 45Kevin

    45Kevin

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    Up here when work needs to be done on pipes that are in or under frozen ground, a line of split 50 gallon barrels are layed over the ground and a coal fire is put under them. After 24 hours or so the ground is thawed down to the frost line.

    Since you probably don't have the split 50gal drums, or the coal, why don't you construct a tent of plastic over the length of frozen pipe. It will be like a green house and warm up the ground under it.

    You get lots of sun there, right?
  15. KLF

    KLF Frame waxer

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    Sorry for the confusion, I meant to say "culvert", not conduit. Corrugated metal pipe (CMP) is a lot less common around here now that PVC pipe has been proven and is easier/cheaper. Our state DOT still prefers concrete pipe (RCP), but that is changing. I usually specify ADS N-12 pipe for drainage, if the client or municipality approves it. Very good stuff, it is corrugated on the outside for strength but smooth on the inside to reduce friction. Doesn't sound like it would be available where you are though.

    Contractor-itus (as I call it) is a common ailment everywhere. I deal with it all the time on the Habitat homes I build.
  16. Southern Colorado coal is abuntly available here. Splitting 55 gallon drums would not be difficult. Now, do these split drums have a vent hole on top? I like the idea.

    A portable cold frame type greenhouse would be a help. This time of year it is not so sunny and there is lots of wind. It could work but would take a lot of time. The greenhouse could be used later for gardening and getting a jump on the growing season.
  17. I've used the trick of laying down 2" rigid insulation over an area where I needed to dig. The ground temperature below frost depth then comes to the surface.
  18. 45Kevin

    45Kevin

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    I don't know if the split drums have a vent. I just see them in a long row here and there during the winter. I would make sense though.This would be the most effective way, albiet the most difficult.

    When I said green house, I meant an eight foot wide roll of plastic in a tent shape that was perhaps 3 feet wide and 1 foot high on a 2x2 frame. You have a 15 foot lenght of frozen pipe. Get 7 2x2x8 pieces of lumber and make 4 3x2x2 triangles. Then connect the triangles at the top with 8' lenghts. Put rocks or pieces of firewood the keep the plastic tight.
  19. I wonder if it would warm the ground fast enough to avoid re-freezing at night when temperature drops into the low teens or single digits?
  20. mooker82

    mooker82

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    Heated pressure washer. Get 1/2 inch PVC or plastic conduit and cap the end. Drill a small hole in the end cap. Attach it to the pressure washer using a threaded connection. Shove it into the clean out and keep adding sections to the pipe until it is to the clog and then spray away. Should be similar to how you would trench under a driveway. I would block behind the clean out to keep water from flowing into the lines inside. It will be really nasty.

    You could also try a power snake with a root cutter to get a small hole through it. Then clear the rest with really hot water.
    Last edited: Jan 29, 2013

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