# how deep to bury thermo pex for oWB?



## Madspeed (Sep 9, 2008)

I've heard conflicting stories and would like some input from those of you that have an OWB. How deep did you bury it? I was thinking like only 2' mainly due to the mountainous rocky terrain here where I live. I have heard anywhere from 18" up to 4 friggin feet!! No way I get get that deep here without a big arse trencher!


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## MS-310 (Sep 9, 2008)

Keep it deep about 42", if you keep the temp up on the outside of the pipe it will lose less heat....


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## Slick (Sep 9, 2008)

I'm also in PA...I'll be using thermopex from CB...my dealer said at least 12" and much more than that isn't needed...it's rated to run ON the ground and he's done that for winter installs then buries in the spring....snow doesn't melt off it above ground so I can see why going very deep isn't needed. I'd say it depends on your insulation of the pex your using....weak insulation go deeper, good stuff not as much need.


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## fletcher0780 (Sep 9, 2008)

It really depends on your water table. If you ground is dry down to 42" put it there, go as deep as the water table will allow. I wouldn't bury any shallower than 18" even if you have a high water table.


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## ngzcaz (Sep 9, 2008)

What no one seems to be mentioning is that according to the National Weather Service in our area ( I live in the Poconos of NE Pa. ) the frost line is 21
inches. Since your pipe is well insulated the depth doesnt much matter. Zoning regs probably require 2 ft for the electric line and you dont need it deeper than that. Finally and also important, make sure the outside pipe ( pvc or drain ) is seamless so that water doesnt get in. 
Good luck..


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## Butch(OH) (Sep 9, 2008)

Mine is Urecon but I think the insulating factor is close to same. I planned on 30" but we found a huge rock that we had to go over and the line is only about 24" there. Been in service over two winters now and at no time have I ever been able to see any difference in the snow cover over the line so I would assume heat loss is minimal. Id put it in as deep as you can without a huge hassle and forget it.


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## jeeptj19992001 (Sep 9, 2008)

i would go down below frost line, for construction, the frost line for that area if i recall correctly is 42". you can call your code officals for that info.


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## Madspeed (Sep 9, 2008)

I'll probably use the CB thermopex


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## zeliespecwriter (Sep 9, 2008)

*How Deep*

Hi Madspeed,

We installed an uninsulated 3/4 inch underground water line from the house to the barn, a total of 200 feet, buried 36 inches in 1998 here in WPA. It has never frozen and we have never had a problem, so when we installed the insulated pex piping for the OWB, we only went down to 24 inches to top of pipe/conduit. The electrical conduit was placed just above the water pipe, about a 2-4 inches. It is only 65 feet from the house. There is no temperature drop. We also placed masonry sand around the pipe before backfilling. Someone on here on another thread said that should also help keep the pipe warm. Did the same with the barn water line. I have also read about putting rigid insulation above the pipe; not sure if that would help. Also, the comment about ground water (and drainage water) is correct. Try to keep the pipe in dry soil. Good luck digging!


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## Madspeed (Sep 9, 2008)

I have one section where there will be running ground water over my pipe, do you think I should SLEEVE it with a larger diameter pipe and insulate between them?


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## rx7145 (Sep 9, 2008)

I have Urecon and only went down a foot. No problems.


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## mtfallsmikey (Sep 10, 2008)

I went down 36-38" on both loops. Another increasingly popular method is to foam the trench with the lines inside, but not any real cost savings...my CB dealer sells their insulated lines now for $12 / ft.


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## fletcher0780 (Sep 10, 2008)

Madspeed said:


> I have one section where there will be running ground water over my pipe, do you think I should SLEEVE it with a larger diameter pipe and insulate between them?



I would, if water gets inside your outer jacket and makes contact with the pex it will wick away a lot of heat.


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## LTREES (Sep 10, 2008)

Ground water + pex-pipe = loss of heat  
definitely insulate between the pipes, insulation I assume is better the an air gap in between. But, then again, thermo-pex (CB) can stay on the ground in the snow. Maybe just run it straight through your wet land. Call a CB dealer.


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## ms310 (Sep 10, 2008)

i went down 48" just because that is the frost line here, the central boiler and heatmore guy told me 18" but, i just figured if i am digging with a backhoe i might as well keep going. Besides that i like to run a backhoe so the deeper i dug the longer i got to play


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## Scootermsp (Sep 10, 2008)

*CB Thermo PEX*

I trenched about 20". The OD of my CB pipe is 4 1/2". I borrowed a friends Milwaukee coring machine and cored a 5" hole in the foundation. I ran 12/3 direct burial cable through the hole. Next I put 2" of utility sand into the trench, Laid the Thermo PEX, then covered pipe and electrical cable with 6+ inches of utility sand. As for the pipe I siliconed the outside, filled the gap with GREAT STUFF, then siliconed the inside when dry. Saturday night we got 6" of rain from TS Hanna and there was no evidence of even a drop 
My CB dealer told me 12" is fine, mine is at about 18". Good luck!


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## zeliespecwriter (Sep 12, 2008)

Two thoughts for your running water problem: One is what you mentioned about with another pipe but wrap the pipe with a waterproof membrane like the "peel-and-stick" stuff they use on foundations (note the material that they use as ice and water dam for roofing is the same material). Watch, this stuff is very sticky. The other thought is to pipe the running water; provide the running water a source to run over your pipe without getting down to your pipe. I asked around to the plumbing and civil engineers here. Not sure where to put that on my timesheet. Maybe there are other civil engineers that have a thought.


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## Madspeed (Sep 12, 2008)

Thanks for all the nput. Piping the ground water would be next to impossible without altering the entire landscape. I live at the bottom of the crest of a mountain and get lots of runoff. I have a swell cut into the upward slope of the bank behind the house that gathers all the rain runoff and takes it way from the house. Now this is only about 2 foot wide. This is the ground water that I need to run my thermopex under. I can try and take a pcture and post tomorrow. Might put it a lil mor einto perspective.


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## Madspeed (Sep 12, 2008)

With the location of my owb, there is no way around going through or across this runoff swell. I won't be cutting in my trench until I'm sure exactly which way to handle this, as I dont want the runoff then following the trench towrds the house!:smoking:


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## Madspeed (Sep 12, 2008)

I was thinking more on the lines of taking the 4" thermo pex and running it through a section of 6" ads drainpipe for the area where it must go through the water runoff swell. This would keep it better insulated and prevent anyground water from stealing heat !!


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## ramrod98 (Feb 7, 2010)

Slick said:


> I'm also in PA...I'll be using thermopex from CB...my dealer said at least 12" and much more than that isn't needed...it's rated to run ON the ground and he's done that for winter installs then buries in the spring....snow doesn't melt off it above ground so I can see why going very deep isn't needed. I'd say it depends on your insulation of the pex your using....weak insulation go deeper, good stuff not as much need.



I have a central boiler and called hem on this question. My dealer told me to dig 12 inches. Central boielrs answer was------ We are in minnosota and the weather here is a lot colder than in Pa. The guy quoted his as being covered with 2 inches of dirt. I have 6 inches over mine and drive heavy equipment over it all the time with no problem(due to the dealer telling me he drives all his mahcinery over his. ) I was told from central boiler that if the fire goes out you have many hours to get things fixed before having to worry about pipes freezing. I just love this stuff ! I don't get any degree drop from furnace to hot water heater at all.


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## tibikedad (Feb 7, 2010)

It seems to me that if "you have many hours before anything freezes", that you are indeed losing heat at that depth (or it would never freeze). Doesn't it make more sense to dig it deeper, and never have to worry about your line freezing?


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## abohac (Feb 7, 2010)

I went 4 feet (frost level). Never had a problem.


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## Penguins87 (Feb 7, 2010)

I live in S.Wyoming Cty,PA. I dug my ditch down two feet and 80' long. Then laid the thermopex in it. We have very sandy loom type soil. I have absolutely no snow melt on the service and less than 1/2 degree heat loss (.28)from my OWB to the first HX. I suggest going as deep as you want but no need to over do it.


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## goosegunner (Feb 7, 2010)

I don't get the Bury it 12-18 inches deep. At $12 dollars a foot why take a chance of damage if you ever drive over it?

I find it hard to believe the pipe is so good you can drive over it when it is 12 inches down. What ever happened to "Do it right do it once"?



gg


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## ramrod98 (Feb 7, 2010)

goosegunner said:


> I don't get the Bury it 12-18 inches deep. At $12 dollars a foot why take a chance of damage if you ever drive over it?
> 
> I find it hard to believe the pipe is so good you can drive over it when it is 12 inches down. What ever happened to "Do it right do it once"?
> 
> ...



I see your concern. However--don't knock it when you don't have the proper answer researched. I have had every type of equipmentand trucks over this line that has but 6 inches of dirt on it. I also questioned why not buried under the frost line as my dealer told me 12 inches tops. I called central boiler direct to check this out. again, i was told 2 inches of dirt is plenty and buried in the frost line means nothing as it is running hot water. i have no antifeeze installed. I did what the dealer told me and what the manufacturer told me. All is well with their specifications. I have not sprung any leaks yet, and doubfully will. You can set yours up as you wish. When i said to central boiler about being in the under the frost line they thought i was nuts. So i buried it deeper than they told me---i went 12 inches deep in most places. right before the boiler i hit ledge so have about 2 inches of dirt on it. I watched my dealer drive over his with his truck that had 3 central boilers on it. He told me he does this all the time, as it goes under a drive he has. i just had a skidster(logging machine in here to drag out a cherry tree from my back yard---yes-----right over the thermopex without a problem. just letting you know how mine is set up as per dealer and manufacturer specs. Not telling you to do it this way however. You do as you wish. I understand your concerns. I had the same concerns also until i had the facts straight.


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## Iska3 (Feb 7, 2010)

I used a pipe called ThermoFlex. It's something like the CB ThermoPex but only $8.10 per foot and free shipping. I went down 24 inches or just above the water table. The pipe is seemless so the water doen not concern me. In Minnesota our frost can go down a good 4 ft but we also get a lot of snow so this does insulate the ground. I have a 130 ft run and no heat loss in my pipes but installing the pipe took a little doing. I was told not to foam my trench because some foam will hold water. 

Do not skimp on your undergound pipe.


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## goosegunner (Feb 7, 2010)

ramrod98 said:


> I see your concern. However--don't knock it when you don't have the proper answer researched. I have had every type of equipmentand trucks over this line that has but 6 inches of dirt on it. I also questioned why not buried under the frost line as my dealer told me 12 inches tops. I called central boiler direct to check this out. again, i was told 2 inches of dirt is plenty and buried in the frost line means nothing as it is running hot water. i have no antifeeze installed. I did what the dealer told me and what the manufacturer told me. All is well with their specifications. I have not sprung any leaks yet, and doubfully will. You can set yours up as you wish. When i said to central boiler about being in the under the frost line they thought i was nuts. So i buried it deeper than they told me---i went 12 inches deep in most places. right before the boiler i hit ledge so have about 2 inches of dirt on it. I watched my dealer drive over his with his truck that had 3 central boilers on it. He told me he does this all the time, as it goes under a drive he has. i just had a skidster(logging machine in here to drag out a cherry tree from my back yard---yes-----right over the thermopex without a problem. just letting you know how mine is set up as per dealer and manufacturer specs. Not telling you to do it this way however. You do as you wish. I understand your concerns. I had the same concerns also until i had the facts straight.




A little sensitive....I wasn't knocking it. It just seems odd that you can drive over any pipe with 2 inches of dirt over it and not have compression. 

I believe it is an outstanding product but at $12 a foot I wouldn't be driving over it 2" under, But that is just me.

gg


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## Iska3 (Feb 7, 2010)

goosegunner said:


> A little sensitive....I wasn't knocking it. It just seems odd that you can drive over any pipe with 2 inches of dirt over it and not have compression.
> 
> I believe it is an outstanding product but at $12 a foot I wouldn't be driving over it 2" under, But that is just me.
> 
> gg



I have the ThermoFlex and put mine down to 24 inches for this same reason. Granted, you can get by with 18 inches or less if you are not going to drive over it. Come this spring when the ground is soft I know what happens. I had me septic line down about 3 feet and when the tractor drive over it will a load of manure, the line was ok for a few times but by fall, I was digging up that line. I have my pex down to 24 inches until I get by my boiler and then I went down to 3 feet and better just for that reason.


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## gwiley (Feb 7, 2010)

I have my lines wrapped in a foam jacket and a heavy platsic sleeve and about 12" down but I see snow melt above them - especially after a lot of liquid water saturates the ground. I am planning on digging them up and either running them through new insulation or reaplcing with thermopex.


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## Iska3 (Feb 7, 2010)

gwiley said:


> I have my lines wrapped in a foam jacket and a heavy platsic sleeve and about 12" down but I see snow melt above them - especially after a lot of liquid water saturates the ground. I am planning on digging them up and either running them through new insulation or reaplcing with thermopex.



You might want to look in to ThermoFlex with an "F" Saved me about $4.00 per foot and no heat loss here in Minnesota If I were to do it again, I'd buy the same stuff. Even thinking of runnin a water line fron the barn to the garage with it this summer.


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## tinman460 (Feb 7, 2010)

I put mine at 2ft the first time and was losing 20* over a 100ft run, dug it up and last 3 years I lose only 5* if that after digging to the 4' mark. Take it from me do it right the first time.


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## pwl (Feb 8, 2010)

Mine has been in for 5 years. The top of the Thermo-Pex is down 8 - 10". I drive over it with everything, no issues.


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## nparch726 (Feb 8, 2010)

Dug my ThermoPex down about 30" on my 60' run. I backfilled about a foot around the pipe with sand, not sure if it helps any for insulating, but I feel a bit better about driving over it with sand backfill than with rocks and big chunks that could poke through the pipe if enough weight or force was applied.


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## hardy steve (Feb 9, 2010)

I went down 36".I have 4 lines I wrapped together in same pipe insulation.Then put in 4" white pvc and burried.It still is the first strip of yard to melt.But the heat difference from owb to hx is on about 6-7deg.It works


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