Frozen fill dirt on water line?

[Snobdds]

In Wyoming, frozen ground from November through March is just a way of life. If everything had to wait until it wasn't frozen, nothing would get done. Here, ground heaters are everywhere and rental places keep a large inventory going. See if you can rent a ground heater and warm up the top soil and bury the pipe.

Here's the idea...

I would thaw the trench and the fill.

 

[jenkinsph]

I bought some bags of topsoil and they are thawing in the house. Going to put those on Thursday.

In a separate note I noticed I have several sections where the original trench dirt has settled quite a bit (I'd say 14-18" in some places. The original line is buried 36-40" deep - do I need to get more backfill or just use plastic,etc? Overall I would guess 200ft of the 600ft are like this

Can you drag a rake over it and smooth it out?

 

[Streetcar]

I bought some bags of topsoil and they are thawing in the house. Going to put those on Thursday.

In a separate note I noticed I have several sections where the original trench dirt has settled quite a bit (I'd say 14-18" in some places. The original line is buried 36-40" deep - do I need to get more backfill or just use plastic,etc? Overall I would guess 200ft of the 600ft are like this

In areas that have settled, just fill the depression.
Frozen soil will lead to settlement.
If surround soil is not frozen, it will melt the frozen soil
In Cincinnati, we have no frozen soil, how deep is soil currently frozen in sunbury

 

[Nic3456]

In areas that have settled, just fill the depression.
Frozen soil will lead to settlement.
If surround soil is not frozen, it will melt the frozen soil
In Cincinnati, we have no frozen soil, how deep is soil currently frozen in sunbury

Last I checked maybe a couple of inches are frozen

 

[RNeumann]

I bought some bags of topsoil and they are thawing in the house. Going to put those on Thursday.

In a separate note I noticed I have several sections where the original trench dirt has settled quite a bit (I'd say 14-18" in some places. The original line is buried 36-40" deep - do I need to get more backfill or just use plastic,etc? Overall I would guess 200ft of the 600ft are like this

The idea behind the depth below grade to avoid freezing the pipes is predicated on soil acting as an insulator. I don't know that plastic will help this much. The final fix will be to bring the depressed areas back up to grade. You mentioned a rake for the task. That sounds like a lot of raking at 200' 14-18". Hopefully a machine could come in and do the task or find a few truck loads of thawed or dry material to throw on top.

Sounds like you are on the right track with this project. Tough to fight Mother Nature when it comes to winter water line work but I see a bright future for this project!

 

[Billrog]

Actually it doesn't make a lot of difference what you cover the ground with it will help to some degree. Every winter I end up burying a few horses for people & have found if I look around the farm and find anything on the ground to move or under a large tree the ground is either soft or barely froze. So anything you cover the ditch with will benefit. Snow is a good example if it snows before it freezes the ground stays thawed.

 

[sixdogs]

I trenched a waterline a couple of months ago but left a pit open where I made a connection going from a 2 inch to 1 inch pipe. The water is getting turned on next week but the ground is fairly frozen. I will backfill that same day as soon as we test the line but is that going to provide any insulation/protection if using frozen backfill? In central Ohio and current daytime temps for the 15th are expected to be a high of 19/low of 9

A trick we used in the far north was to put down a foot wide strip of 2" thick foam board insulation. First, it cushioned the fall of the dirt and second was the insulation. Pick the big rocks out but we never had a problem doing it this way.

 

[ovrszd]

Cover it with some stone first. How deep is the line? May want to leave the water running abit just for insurance until the ground has a chance to warm the backfill up a bit.

Never put stone around a water line.

 

[RNeumann]

A trick we used in the far north was to put down a foot wide strip of 2" thick foam board insulation. First, it cushioned the fall of the dirt and second was the insulation. Pick the big rocks out but we never had a problem doing it this way.

Good trick!

Or local building inspectors will approve 1' less depth for every 1" (R5) of rigid. We can use a max of 2". Normal depth here is 44-48" so we could go to 2' plus 2" of rigid in an area with a large bolder or similar that prevented digging to the standard depth- very rarely used but a vital trick!

Doing underground in my previous location we would use "sand" or "base". Then in my current location they use "crushed stone" or "stone dust".

I'd assume the concern is larger stone that could damage the pipe? Like 1/2" and above?

 

[PILOON]

Good trick!

Or local building inspectors will approve 1' less depth for every 1" (R5) of rigid. We can use a max of 2". Normal depth here is 44-48" so we could go to 2' plus 2" of rigid in an area with a large bolder or similar that prevented digging to the standard depth- very rarely used but a vital trick!

Doing underground in my previous location we would use "sand" or "base". Then in my current location they use "crushed stone" or "stone dust".

I'd assume the concern is larger stone that could damage the pipe? Like 1/2" and above?

I also have more than just a few done that way and it works.
Also not disturbing the snow covering is a factor, example being lines under a driveway need more protection as snow actually insulates.
Locally some city mains actually froze even down to 12 ft where unprotected like under a street.
Our city now even uses foam to protect culverts as it saves lots of steaming out come spring.

 

[Nic3456]

Is there any type of roll insulation that I could use for my 200 ft of depressed ground? My trench is about 6in wide - just thinking if could roll something out as a temporary measure. They now aren't turning the water on until tomorrow when it's a balmy 25 haha

 

[RNeumann]

I'll say no- but anything is possible. The insulation we were discussing would placed on top of the pipe and be installed prior to backfill. You may be over thinking this or doubling your efforts. Dirt is the final solution so anything you do now will get redone at some point if it's not dirt. I'm just trying to save you time and money.
If you can't get dirt on it until spring don't drive or disturb the snow in those areas- it will help insulate it.

If you get an unusual cold snap run a bit of water during those few days. I'm guessing that would amount to less than $10 worth of water which is far less than any of the other temporary solutions.

 

[Nic3456]

Thanks - I was hoping to do that - but wasn't sure how risky that would be. We are supposed to get into the mid 30s for most of next week. Hopefully the ground will thaw enough for me to add some dirt and use my box blade

 

[sixdogs]

A trick we used in the far north was to put down a foot wide strip of 2" thick foam board insulation. First, it cushioned the fall of the dirt and second was the insulation. Pick the big rocks out but we never had a problem doing it this way.

Good trick!

Or local building inspectors will approve 1' less depth for every 1" (R5) of rigid. We can use a max of 2". Normal depth here is 44-48" so we could go to 2' plus 2" of rigid in an area with a large bolder or similar that prevented digging to the standard depth- very rarely used but a vital trick!

Doing underground in my previous location we would use "sand" or "base". Then in my current location they use "crushed stone" or "stone dust".

I'd assume the concern is larger stone that could damage the pipe? Like 1/2" and above?

We had a 7 ft frost line and I put down two layers of 12" wide by 2" thick blue foam at five feet down. Never a problem and I have seen guys do similar at 4 or 5 feet. Temps could go to minus 30 or minus 35 but the issue was that it stayed cold from November through spring with little chance to warm up.

By the way, I have been told that frost only travels up and down and not sideways so cutting extra wide widths of foam wasn't necessary. That stuff really holds the heat and the running water provides some. If you care, pushing snow over a water line keeps the frost out too.

 

[RNeumann]

Thanks - I was hoping to do that - but wasn't sure how risky that would be. We are supposed to get into the mid 30s for most of next week. Hopefully the ground will thaw enough for me to add some dirt and use my box blade

You are on the right track! It will work out fine. Enjoy the new building.

 

[quicksandfarmer]

What no one else has mentioned is that frozen ground is as hard as concrete. Just like you wouldn't put rocks directly on the line, you shouldn't put chunks of frozen dirt either. If the pit is 2x3 feet, six inches of sand is three cubic feet, or about 300 pounds. What I would do is go to Home Depot or Lowes -- where they keep the building supplies indoors -- and buy six 50-lb bags of sand. That will protect the pipe. You can then pile chunks of frozen ground over it. That will keep it from freezing. When the ground thaws the chunks will melt and settle, you'll have to fix it up then. I doubt you'll be able to do any landscaping until spring anyway.

 

[jenkinsph]

What no one else has mentioned is that frozen ground is as hard as concrete. Just like you wouldn't put rocks directly on the line, you shouldn't put chunks of frozen dirt either. If the pit is 2x3 feet, six inches of sand is three cubic feet, or about 300 pounds. What I would do is go to Home Depot or Lowes -- where they keep the building supplies indoors -- and buy six 50-lb bags of sand. That will protect the pipe. You can then pile chunks of frozen ground over it. That will keep it from freezing. When the ground thaws the chunks will melt and settle, you'll have to fix it up then. I doubt you'll be able to do any landscaping until spring anyway.

I don't know what everyone was thinking but felt that almost everyone understood these issues and suggested similar solutions to yours. Adding the insulation as many suggested solves the chunky frozen dirt problems and helps to capture ground heat. The OP mentioned buying the bags of top soil that he was warming up in the house.

 

[Nic3456]

Just wanted to give a final update - it worked out perfect. The plumbers happened to be turning on the water while the septic tank guys were still there installing my tanks - plumbers checked the line and then the septic guys filled the pit with some fresh hot dirt from their dig - it was nice and steamy :cool2:

 

[Billrog]

:thumbsup: