# underground piping.



## smangold (Mar 1, 2008)

HI, still contemplating the location on my boiler. Thinking a bit about putting it in my barn. Whats the deal with the encased pex stuff. How deep do you bury it... 48" ,or 24" with some xps insulation closer to grade for frost protection. What about a wet area? Where is the best place to get it?  Thanks Scott


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## EForest (Mar 1, 2008)

Scott,
save your cash and make it yourself with black drainage pipe and pex.
you should bury it below the frost line (42" in our area).
When the ground thaws you can check out my install.
I spoke with Gary again. He's got great ideas.
but thats a story for another thread.


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## Eric Johnson (Mar 1, 2008)

There's some discussion of DIY underground piping in the middle of page 2 in this thread:

https://www.hearth.com/econtent/index.php/forums/viewthread/12722/P15/


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## ebbci05 (Mar 1, 2008)

I would be careful to use the insulated pex stuff that comes in sections and you put if together.  Up by me I know of three or four people who have had water problems.  Even though they sealed the joints water still got in and cooled the water.  Also, I know of one guy that had the water follow the tube inside his house and made quite a mess.  I guess as long as you don't have a high water table and good ground to absorb rain water you might not have a problem.  But I would make sure that the pipe going into your house is higher than the rest.  On mine we had a company come in and spray foam (like greatstuff) and seal the whole thing without any joints.  Gotta go hope this helps


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## Tony H (Mar 2, 2008)

A couple of points on buried pipe do not use any joint connections under ground and you then do not need to get below the frost line.  The common depth rule is 22 to 24 inches deep except at egress points with continuous pipe. It's fine to go deeper if your equipment can handle it most medium sized walk behind trenchers can go 36' or deeper, just make sure to figure your intended depth when you order the pipe.
Standard pex pipe in not prone to cracking under ground however you do need to protect and insulate it also if the area is wet make sure you provide plenty of drainage so the pipe does not sit in water. If possible provide a drip loop where you enter the basement by going down an extra 12 inches a few feet out from the wall and then back up to the entrance hole and fill around the pipe with hydraulic cement.


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## adamant (Mar 2, 2008)

i just trenched today @24'' as per my contractors instruction.


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## JustWood (Mar 2, 2008)

Buy the best  and bury it deep with extra insulation and sand for extra protection. Do it RIGHT the first time. My dad is paying the price for not listening to me last fall.


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## trehugr (Mar 2, 2008)

LEES WOOD-CO said:
			
		

> Buy the best  and bury it deep with extra insulation and sand for extra protection. Do it RIGHT the first time. My dad is paying the price for not listening to me last fall.



What did he do? So all of us know what not to do !


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## JustWood (Mar 2, 2008)

He didn't listen! Do it right the first time !


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## PAPROUD (Mar 9, 2008)

My installer suggested the same idea of buying the pex pipe, enclosing it in insulating foam and putting it into a black pipe, instead of buying the thermopex.  Anyone else doing this?  I believe the cost would be a quarter of the thermopex price.  Looking at a 100 foot run and going to bury it at least 2-3 feet.


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## begreen (Mar 9, 2008)

Local hydronics contractor says drop the tubing into the trench on a bed of 2" foam board, then mix up and pour (or spray) foam over it. He hasn't had a reported failure yet.


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## BrownianHeatingTech (Mar 9, 2008)

BeGreen said:
			
		

> Local hydronics contractor says drop the tubing into the trench on a bed of 2" foam board, then mix up and pour (or spray) foam over it. He hasn't had a reported failure yet.



Maybe not a "failure" (as in, leak), but how does the insulation hold up over the years?  I'm not thinking that the spray foam will survive indefinitely under those conditions...

Joe


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## heaterman (Mar 9, 2008)

I just talked with a guy last Thursday who used the corrugated tube type insulation along with 1 1/2" foam on top for a 1" line set going to his house. He has a 4 foot wide swath of bare ground from the OWB to his house. I calc'd his heat loss based on estimted GPM and actual temp drop in the supply and it's about 135,000 BTU's. That's more than he needs to actually heat his house  The product I'm referring to is the generic 4" tube with a few wraps of foil/foam insulation on the pex. They are all the same, don't let anyone kid you. He ran a rag through the tube to check for water infiltration and it's bone dry, no issues there. As far as I can see you might as well put bare pex in the ground as waste money on that stuff.

The insulated tube that comes in 10' sections works very well, IF you install it correctly. Most failures that I have seen are directly attributable to poor installation practices like improper priming and gluing, the wrong glue, gluing wet or dirty joints, not supporting the tube in the trench and leaving voids underneath it when back filling, back filling with boulders of clay and then running over it to compact, etc. etc. There's a ton of ways you can screw up whatever job you're trying to do.

We lay bare pex of whatever size in the trench and hire a local insulating company to come to the jobsite and spray it with urethane. Virtually no heat loss, waterproof, 5 minutes and the foam is so hard you can walk on it. If you can find someone to do it, that's the best way and not all that expensive compared to other good products like preinsulated pex. It's the only method that I will guarantee.


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## 88rxn/a (Mar 9, 2008)

great ideas here. i ALMOST got some of that thermoPEX of and Ebay company. i will prob. make it myself also. what about using wood chips to HELP insulate in the ground?? not saying to just use the chips alone but as a added insulation suggestion.

i may go to LOWES to see what kind of insulation i can get to do the job right the first time.

and you were talking about priming and gluing? could you explain that better?


> I have seen are directly attributable to poor installation practices like improper priming and gluing, the wrong glue





**edit**
i also may run the electric heat tape through mine for that "JUST IN CASE" factor.


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## Chris S (Mar 9, 2008)

wood chips, or as some call them "lightweight aggregate"  will hold a lot of moisture, eventually rot, and settle- wouldn't be my choice
I've had good luck with the uponor preinsulated product- very low heat loss, about 10/ft though for 1"
Spraying the trench sounds interesting,  but how much did that cost?
Chris


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## smangold (Mar 10, 2008)

I spoke with a boiler guy yesterday about the piping. His thoughts were to dig a 4' deep trench with 6" of crushed stone at the bottom and then two layers of 2" blueboard followed by 4" pvc pipe .Surround the pipe on the three other sides with 4" of XPS also, back-fill, vacuum a rope through it and pull 2 pcs. of 1" pex through. This would allow you two change out the pex if necessary. The stone should be drained to daylight. 4" pvc is pricey though. maybe two runs of 2" would be just as good. Or is there other pipe that would work?


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## heaterman (Mar 10, 2008)

RE: Cost for spraying the trench

You'd have to check locally with an insulating company near you. The company I use, Alper's Insulating out of Traverse City Michigan charges a $75 trip and setup fee which is waived if they're spraying more than 50 or so feet. From there the charges are based solely on the amount of product they use. When quoting a job, I use a figure of $7 per foot for normal 1" or 1/14" pex as my cost and that usually comes out pretty close. For larger sizees of pex it runs a little more. I'm VERY pleased with the way it works. We did one this fall that was 283' long using 2" pex. We wound up with a foam thickness of a good 4-5" on all sides of the pex. The tube is a bit over 2' down and goes under a drive with heavy farm equipment running over it all day. There is no sign of any heat loss even under the drive. Using my Fluke digital thermometer/thermocouple, I can read a temp drop of only .7 to1 degree in the 283' depending on the water supply temp. The 1 degree reading was at 185* water temp.  That's a far cry from the 30*+ I measured at the other poor guy's place last week using the corrugated stuff with foil/bubble/foam/whatever as lining.  

  Insulating the tube is the absolute last place to try a save some $$ by going with a cheaper product. It will cost you more labor, more wood, more wear and tear for the life of the system.

Do it once. Do it right.


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## mtfallsmikey (Mar 10, 2008)

Getting ready to do mine...1" PEX, Armacell insulation, going to try to pull both lines thru 4" ADS, if unsuccessful, do separate runs. The 1" PEX is STIFF! Any ideas on how to unroll on the ground first to get it to take a "set"?


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## Chris S (Mar 10, 2008)

Armacel has very low value!!


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## Tony H (Mar 10, 2008)

mtfallsmikey said:
			
		

> Getting ready to do mine...1" PEX, Armacell insulation, going to try to pull both lines thru 4" ADS, if unsuccessful, do separate runs. The 1" PEX is STIFF! Any ideas on how to unroll on the ground first to get it to take a "set"?



If it's a sunny day lay the pipe out in the sun for a few hours first and then wrap one coil around a tree or other large  round fixed object and secure then unroll against the coiled direction and stretch to another fixed object and let it sit for a while.

This is how I uncoiled the Logstor dual pex insulated pipe that I buried it is about 4.5 inches diameter and quite stiff so I used my ATV and a logging chain to help it along, you can use quite a bit of force just make sure you don't kink the pipe.

When pulling thru the other pipe you might want to use some pulling lube and a helper to make sure it slides thru ok if it's a long run.


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## smangold (Mar 10, 2008)

Heaterman, Are you talking about the closed cell foam contractors spray in wall cavities. Also do you suspend the pipe in the trench or do you use rigid underneath( to allow foam under the pex.) Thanks for all the good info.


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## Chris S (Mar 10, 2008)

Heaterman- 
That seems  like a lot of time , trouble etc. 
I have used Ecoflex ( from uponor)  & found it to be easy & fast to install but expensive.  I'm not sure if what you're suggesting is any less expensive though, or any better.  Did you use one of the prepackaged products & find it unacceptable, or do you believe your installation is better for all of the reasons stated above.   Not even sure of the availability of ecoflex larger than 11/4"

Chris


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## heaterman (Mar 10, 2008)

smangold said:
			
		

> Heaterman, Are you talking about the closed cell foam contractors spray in wall cavities. Also do you suspend the pipe in the trench or do you use rigid underneath( to allow foam under the pex.) Thanks for all the good info.



The product usually sprayed in a house is not urethane based. It's a much different animal. The urethane these guys use "blows" like Great Stuff x 3 and I'm not even sure you can use it in a structure unless it's in a sealed space. When dried (just a few minutes) the foam is closed cell in structure so it's totally waterproof. As I said before, I can put all my 228# weight on a pile of it in maybe 2 minutes. It's very rigid when cured. The installing crew told me they have jobs that are right in the water table with no issues whatsoever and from the performance of their product, I see no reason to doubt them.


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## heaterman (Mar 10, 2008)

Chris S said:
			
		

> Heaterman-
> That seems  like a lot of time , trouble etc.
> I have used Ecoflex ( from uponor)  & found it to be easy & fast to install but expensive.  I'm not sure if what you're suggesting is any less expensive though, or any better.  Did you use one of the prepackaged products & find it unacceptable, or do you believe your installation is better for all of the reasons stated above.   Not even sure of the availability of ecoflex larger than 11/4"
> 
> Chris



I've found that this method gives us a little more flexibility in the installation. It may take a bit more time but it would be minuscule. The bare pex is much easier to handle than the Ecoflex.  Doing it this way, we nearly always wind up with 4" minimum all the way around the tubes which is much better than anything else I've found. Most times it's more like 5-6". 

The guy running the gun in the trench will lift the tubes with his foot and apply a swath under them. The foam blows and begins to harden in about 5-10 seconds at which point he drops the tube on the foam and covers the sides and top. He works his way down the trench in 3-4 foot increments.

Again, when insulating your underground piping, the term "good enough" should not even be in your vocabulary. So what if it's $.50 or $2.00 more a foot, which I have not found to be the case, it's the best money you can spend.


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## DKerley (Mar 11, 2008)

Hello,

My installation required 100" of buried 1"Kitec pipe for the shop heat. The product that I used is made by Urecon (http://www.urecon.com/english/english.html). I buried it 3' deep (within the frost zone as our frost line is far too deep to practically get below). The Urecon pipe is basically 4" PVC pipe with a layer of foam insulation then, a waterproof barrier wrapped around it. The outside diameter then becomes 7". It comes in 10' lengths which you can glue together and then seal the joints. On my installation, there is no measurable heat loss over the total of 160' of pipe length between the boiler and the shop heater.

The product was fairly expensive (about $12.0 ft. plus shipping). The nice thing about it is that I was able to run a potable water line inside the pipe as well after the heating installation was completed.

Cheers


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## smangold (Mar 11, 2008)

Heaterman Would you be able to give me a brand name of the foam product you use ,so I can search for a local contractor. Thank you


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## heaterman (Mar 11, 2008)

Sorry but I don't know a brand name. I do know that the product is a two part system IIRC and is heated before application. If you want to call my guys directly and ask them about the product, here's their number. 231-946-7450. I'm sure they'd be happy to explain it to you. They say they have been using this process on all sorts of underground piping for a long time with no failures.


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## Tony H (Mar 11, 2008)

Here is a web page with some good info on the different spray insulations and links to more specific info on each that may help in finding the right product and getting it installed. 
http://en.wikipedia.org/wiki/Building_insulation_materials


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## trehugr (Mar 11, 2008)

Ive been very interested in this thread. I found this stuff and wondered if anyone has ever used it ?  Would it work for what were talking about here? 

http://www.foampower.com/store/two_component/index.html


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## smangold (Mar 12, 2008)

Thanks heaterman, Ill give them a call. I called my insulation man and he didn't think his foam would be good underground. Trehuger, the Handifoam is available at my building supply house. I think I'll call and see if I can talk to a rep.


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## heaterman (Mar 12, 2008)

Handifoam appears to be much the same, urethane based, two part product although I don't see anything regarding being waterproof. In addition, I see that it's coverage is listed in board feet. Not a very useful measurement when trying to figure out how much will be needed to do a trench. It's not cheap from the looks of it.

The insulating company I use shows up at the jobsite with a F-550 complete with diesel generator to run the 3 phase heaters and 55 gallon drums of product.


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## Bob Rohr (Mar 12, 2008)

My favorite product/ method is the InsulSeal product.  It is PVC pipe with a foam sprayed around it and a water proof liner.  The 10 foot sections glue together, and you tape the seams.  It is available in various r-values.

This provides 3 nice features.  First a consistent r- value, unlike the pipe in coiled drain tube.  It provides a 100% water proofed condiut, unlike the easily punctured black slinky drain products.

It also allows you to install, and remove if needed, the tube inside.

I install a PAP supply and return, and a few extra pex tubes for water and or pulling low voltage lines for control circuits.  The 4" InsulSeal easily handles 6 tubes or more.

Mine has 4- 1" pex lines and 4- 1/2" pex lines inside.

Also run some tube inside to add solar to the roof of your outdoor boiler building.  One 4X8 panel will go a long ways to supplying DHW for a typical family.

 hr


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## Gooserider (Mar 12, 2008)

I like the idea of having a replaceable core, and the flexibility you mention, but there are a couple things I'd wonder about...  

1. How much heat leakage do you get between the pipes inside - not just the supply and returns, but also any other lines - say if you were trying to run a cold water feed for a sink / bathroom in the heater shed, or how much would your low voltage control lines get cooked?  (I know my CAT5e cable is only rated for about 150*)

2. What is "PAP"?

3. I can see how you could get foam around the length of the pipe, but it would seem like there would have to be a gap at the joints - do you fill that gap with some sort of spray foam as well as tape sealing it, or what?

4. How do you deal with less than full lengths of pipe?

5. Are there elbows and other such fittings available for the ends of the run?  I know I would not want to make below grade penetrations through my basement wall, and would far rather come up high enough to go through the sill plate area - wood is easier to drill than concrete.

Gooserider




			
				master of sparks said:
			
		

> My favorite product/ method is the InsulSeal product.  It is PVC pipe with a foam sprayed around it and a water proof liner.  The 10 foot sections glue together, and you tape the seams.  It is available in various r-values.
> 
> This provides 3 nice features.  First a consistent r- value, unlike the pipe in coiled drain tube.  It provides a 100% water proofed condiut, unlike the easily punctured black slinky drain products.
> 
> ...


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## Bob Rohr (Mar 13, 2008)

Gooserider said:
			
		

> I like the idea of having a replaceable core, and the flexibility you mention, but there are a couple things I'd wonder about...
> 
> 1. How much heat leakage do you get between the pipes inside - not just the supply and returns, but also any other lines - say if you were trying to run a cold water feed for a sink / bathroom in the heater shed, or how much would your low voltage control lines get cooked?  (I know my CAT5e cable is only rated for about 150*)
> 
> ...


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## heaterman (Mar 13, 2008)

I like Insulseal also and have used it quite a few times. I 've seen people install it themselves and have problems though. The number one thing is to be careful about the bottom of your trench and make sure the Insulseal is well supported. Backfilling should be done with a normal amount of care also. I recently ran into a homeowner who had installed it himself and run into problems with water entering the pipe. Obviously he had a joint come apart somewhere underground and it allowed ground water to follow the tube into his basement. His yard was solid clay and upon questioning him it became clear that there were probably a lot of void under the tube when he backfilled. The trench was only 30" or so deep and he ran his backhoe over it to compact the soild back down after backfilling. I'm guessing that he had a pocket under the Insulseal that allowed it to flex and break when he did that. Definitely not the fault of the product. As with all thing, you have to use your head and consider the consequences of an action before doing it.


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## Tony H (Mar 13, 2008)

I agree with heaterman the product is good but many installations fail due to poor installation. If you hire and experienced contractor you will probably not have a problem however many non experienced persons will have trouble with breaks at the joints some to to poor prep, traffic over top , and frost heaving. If you take the time to bury it deep and level support it well and fill around the pipe with sand and then pulverized dirt (not clay/chunks) you should be ok provided you do not drive a backhoe over it right away. Water in the backfill and allow it to settle naturally for a few weeks adding more fill as it settles.


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