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Join Date: Jul 2017
Posts: 14

Sewer Line Freezing

08/02/2017 4:41 PM

Hi there,

I currently work in a quad trailer and our sewer line froze this past February. I need you guys help so it doesn't freeze this coming winter.

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here is what was already done in the line in the past, 2009:

Maintenance dug-up the area using Kabota tractor. There was a hard layer of asphalt/concrete directly above the pipes. The kabota was unable to break thru this layer so manual labor was used. They located the "T" about 12" below ground level. There is a short sweep installed and it is going the correct way. The "T" was located at a belly in the main line. They also identified a solid single strand of insulated copper wire running alongside each pipe. They were unsure what that was for but could aid in located the pipe in the future.

Dug out Clean-out and replaced coupling and screw in cap, and installed a new cast iron lid and ring.

Finished the heat tape installation. Pulled new conductors for the Gardener's Garage. Completed the power feed to the Gardener's Garage. There is a new receptacle mounted under the west trailer just inside the access hatch. The controller for the heat tape is there also. It has GFCI. A new breaker was installed in the stand-alone lighting panel, (not one of the lighting panels mounted on a trailer,) in position #8. The heat tape was wrapped around the 4" pipe at a rate of 3' of tape to 1' of pipe. The pipe was then buried and concrete poured over the end of it.

Back filled with 5/8 minus and poured weak concrete into the trench and the south clean-out

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so, all that work was done in 2009 and it froze this last year. What can I do so it doesn't happen again this coming winter?

please advise

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Guru

Join Date: Mar 2007
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#1

Re: sewer line freezing

08/02/2017 4:56 PM

Well the first thing you should have done is insulate the pipe....

https://www.grainger.com/category/pipe-insulation/insulation/plumbing/ecatalog/N-r6b

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Power-User

Join Date: Jul 2016
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#6
In reply to #1

Re: sewer line freezing

08/03/2017 9:46 AM

including any part above ground, but in unheated space, conducting your heat trace heat back up the pipe, away from where you need it (where some water must remain).

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Guru

Join Date: Jul 2008
Posts: 1222
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#2

Re: sewer line freezing

08/02/2017 5:05 PM

I don't know SH#* about sewers (sorry, I couldn't resist) but for a first level answer you need one of the following:
1) more heat
2) better insulation
3) global warming

Well, I'm not real hot on the third one so let's go with the first two. Anyone trying to help will probably want to know details about the heat tape you installed. They will want to know if the area is something like an active parking lot (insulation not reasonable) or a pad out back that is not used in the winter (4x8 sheets of styrofoam seem good when the choice is no toilet). I don't know what else is important but anything you can think of related to heating, cooling and insulation is probably good to add to the post.

Is the pipe PVC or cast iron? What state/country are you in?

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Guru

Join Date: Sep 2012
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#3

Re: sewer line freezing

08/02/2017 5:06 PM

How deep is the frost level in your climate? All water/sewer pipes must be below this depth. Heat tape has a finite life, and should only be used on exposed pipes and then insulation applied. Your description of pouring concrete over this sewer pipe makes the problem worse, as it conducts heat from the ground darn good, enabling the frost to go deeper. As well complicates future maintenance.

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#4

Re: sewer line freezing

08/02/2017 6:45 PM

You should have used a John Deere. Nothing runs like a Deere!

Bury the line deeper, as has already been suggested.

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Guru
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Join Date: Oct 2009
Location: Maine, USA
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#5

Re: sewer line freezing

08/02/2017 10:54 PM

Bury the line deeper and don't remove snow from above it...if it snows there. Here in Maine we put things like this down at least 4 ft below ground level.

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Guru

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#7
In reply to #5

Re: sewer line freezing

08/03/2017 2:11 PM

the trick is get below the frost line with any uninsulated pipe.

You have the option of boxing up around the pipe (after insulation), to decrease cooling rate due to extreme temperatures outdoors.

Heat coupled from the housing unit floor should help maintain the box temperature above freezing.

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Guru

Join Date: Apr 2011
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#8

Re: Sewer Line Freezing

08/03/2017 7:14 PM

• Put skirting around the trailer, and otherwise create a sealed envelope between the bottom of the trailer and the ground below. Consider addind a layer of insulation inside the skirt. This will also make it easier to heat the trailer.

• Don't turn off the heat to the trailer, just set the thermostat to a low temp to save energy when not occupied.

• When the forcast is for a hard freeze, leave some water running. Alternately, during a hard freeze, set up a slow trickle of denatured alcohol or brine...perhaps poke a small hole in the bottom of 5 gallon bucket and put it where is drains to the line.

• Avoid any low sodium diet.

• Add additional antifreeze heating cables/tape to the line.

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Guru

Join Date: Oct 2014
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#9

Re: Sewer Line Freezing

08/03/2017 11:08 PM

There are many examples of fine American out houses that sustained pioneers. They operated well, without the need for sewage piping.

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Guru

Join Date: Apr 2009
Location: USA, Florida
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#10

Re: Sewer Line Freezing

08/04/2017 1:45 PM

Skirt the trailer as stated in #8 below.

Apply 12" minimum of sawmill grade sawdust, which will provide several years of heat from decomposition.

You may have to water the sawdust every few months.

Also apply treatment for termites if you have them there.

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