water pipe in ditch, how much straw freeze protection

[coffeeman]

Merry Christmas & best to all.

I have a water pipe in ditch. Line has water in it. Line is capped. Couldn't finish before rain & snow.

I have covered pipe with about 2 feet of straw. Temp going down to 7 in couple days. Will hang there for
3 days or so. It's 20 today........

Do I have enough protection from freeze?

Cheers.....Coffeeman

 

[LD1]

I think its gonna be impossible for anyone to answer. Too many variables.

How thick is the straw? or loose and fluffy?
How wide is the trench (narrower is better)
How cold did the ground inside the trench get (frozen) before covered with straw?
How deep is the trench?
How much exposed pipe do you have? and IF if freezes and breaks....whats the cost of a do-over?
Etc Etc.

Gut feeling is a trench no more than a foot wide, and at least 2-3' deep, and covered with fairly dense straw...the earth is gonna provide enough warmth to keep water from freezing. But a wider trench is gonna cool faster. And a shallower trench is going cool quicker as well as not get as much warmth from the ground

 

[Redlands Okie]

One idea might be to keep some water running thru it if possible. Drip at a faucet or some such. Running water usually does not freeze.

No idea on the amount of ditch you have but some plastic liner on top of that straw or ditch to help keep the warm air from below down and the cold air on top out would help a lot. Also would keep the straw a bit dryer and so that would help also.

 

[4570Man]

Why not just drain the line?

 

[ultrarunner]

I remember blowing out lines with compressed air in preparation for winter... not sure if many do this anymore?

 

[rgr33]

If it’s schedule 40, and charged already, you might be in trouble there.

I think the advice to isolate it and blow it out with air is the safest play.

 

[coffeeman]

I think its gonna be impossible for anyone to answer. Too many variables.

How thick is the straw? or loose and fluffy?
How wide is the trench (narrower is better)
How cold did the ground inside the trench get (frozen) before covered with straw?
How deep is the trench?
How much exposed pipe do you have? and IF if freezes and breaks....whats the cost of a do-over?
Etc Etc.

Gut feeling is a trench no more than a foot wide, and at least 2-3' deep, and covered with fairly dense straw...the earth is gonna provide enough warmth to keep water from freezing. But a wider trench is gonna cool faster. And a shallower trench is going cool quicker as well as not get as much warmth from the ground

Straw, some fluffy, some thick. trench is about 4 ft wide.
Temperature 55 + on day of installation. Covered with straw about 45 degree.
About 4 feet exposed. Line from T connection, No shut off at T. So caped line has water full pressure.
Ran out daylight. Next day rain mud all day. Then snow & cold.
Just replaced 300 foot with new blue water line from old black plastic.
If breaks water will gush at maximum & shut other building down.
Cost of repair a freeze is small, except for water bill. Shutting meter down, faster the better. Of course aggravation too.
Trench wide in this section. A connection to 30 ft line leaked down stream. Capped & shut new line. Must replace extra 30 ft.
Thus, repairs in December can be tricky.

Cheers....Coffeeman

 

[Industrial Toys]

That's the question. Are you actively using it? Did you say you capped it? I had my main water line freeze a couple of years ago, and after a huge effort to get it unfrozen, left a tap on a fast drip til the spring.

 

[Mendonsy]

How deep is the normal frost line where you live?? I would suggest at least twice that much straw.

 

[Kentuckyfarmer]

Throw some plywood over the ditch and with the straw in the ditch also put some over the plywood and you'll be fine. I can't tell you how many time I've had to leave the ditch open because of time not able to finish the job and was freezing weather and used plywood and straw to protect the pipe. Main thing is try and keep the wind from blowing in the ditch.