In ground piping

[Paul]

In other threads I have seen mention of people using pex through culverts and then foaming them in as a superior way of insulating. The installed that I have contacted has been steering me away from this as he has seen problems with the foam becoming wet from ground moisture and causing large heat loss. Is there some foam that is guaranteed to be water proof over time. I live where there is a high water table and do not want to get into water troubles with foam if there is a risk. I have been recommended to do with a layered prepackaged piping. Any suggestions?

 

[heaterman]

In other threads I have seen mention of people using pex through culverts and then foaming them in as a superior way of insulating. The installed that I have contacted has been steering me away from this as he has seen problems with the foam becoming wet from ground moisture and causing large heat loss. Is there some foam that is guaranteed to be water proof over time. I live where there is a high water table and do not want to get into water troubles with foam if there is a risk. I have been recommended to do with a layered prepackaged piping. Any suggestions?

The tube wrapped in layers of 1/4" foam, stuffed in corrugated drain tube would be the last choice for a high water table environment. You may as well just put bare tube in the ground. The corrugated drain tube is very light gauge material. As such it can be crushed and/or perforated easily allowing ground water to enter.
Urethane foam will not absorb any water. It is commonly used for waterproofing and insulating basement walls and underground tanks. I don't know where people come up with that type of false info.

 

[Rick Stanley]

Heaterman,

This is the stuff Garn recommended to me www.thermopex.com as being "bullet proof " and to put it below the frost line. It's their fear that even closed cell urethane spray foam may absorb moisture over time even with the water table NOT being an issue. If high water table IS an issue, they want a separate drain pipe installed to carry water away from the boiler pipes even with Thermopex.

So, possibly some of the info is coming from Garn. I know it is in my case.

Rick

 

[heaterman]

Heaterman,

This is the stuff Garn recommended to me www.thermopex.com as being "bullet proof " and to put it below the frost line. It's their fear that even closed cell urethane spray foam may absorb moisture over time even with the water table NOT being an issue. If high water table IS an issue, they want a separate drain pipe installed to carry water away from the boiler pipes even with Thermopex.

So, possibly some of the info is coming from Garn. I know it is in my case.

Rick

I'm confused. This is the stuff Garn recommends and sells.( (broken link removed) )

I don't know where the thermopex comes from but it's not directly from Garn. Maybe it's what your dealer has available.

 

[Rick Stanley]

Sorry, I confused thermopex and microflex as being equal, maybe they aren't.

Now that you mention it, I don't think my dealer specified brand name, only TYPE of product. If Garn sells Microflex probably that's what he meant. He agrees with you though, as does Garn, that a couple of pieces of pex wrapped in a quarter inch of bubble/foil/insulation, stuck loosely into a length of flexible drain pipe is no good.

But he also said that Garn was leery of the closed cell urethane spray foam taking on moisture, over time.

I have contacted an insulation company that claims to have a product that WON'T take on water, however.

The microflex type product seems the safest bet to me, at the moment, I guess

 

[MrEd]

Any pricing available on the microflex product? I have yet to find anything that looked like it would perform well over a long period of time for anything less that $28+ per foot. Even for my approx 50' run we are talking $1500, plus the shed I was going to put up to house it all.

Pretty much decided (today) that I will go with my original plan to put my Tarm in the attached garage, and use the extra money to get the storage up and running. really, really like the idea of having it a dedicated boiler shed with attached woodshed, but the cost of doing it 'outside' just kept on escalating.

I could change my mind if someone could point me to a solid underground pipe solution that won't cost me an arm and a leg....

 

[Sawyer]

Sorry, I confused thermopex and microflex as being equal, maybe they aren't.

Now that you mention it, I don't think my dealer specified brand name, only TYPE of product. If Garn sells Microflex probably that's what he meant. He agrees with you though, as does Garn, that a couple of pieces of pex wrapped in a quarter inch of bubble/foil/insulation, stuck loosely into a length of flexible drain pipe is no good.

But he also said that Garn was leery of the closed cell urethane spray foam taking on moisture, over time.

I have contacted an insulation company that claims to have a product that WON'T take on water, however.

The microflex type product seems the safest bet to me, at the moment, I guess

Hi Rick, I had the same experience with Paul at Garn, he recommended Microflex, saying he was concerned with the foam absorbing moisture over time.

I do like the idea of the foam in trench and being new to this forum, respectively to others who use this method, question the application of the foamed trench if I cannot find documentation. It do like the additional insulation qualities and the reduced cost of the foamed in trench. However I would hate to find out that in 5-10 years I was dumping my heat into the ground because the foam became saturated and lost its insulation capability.

I now have a call in to the insulators for documentation on waterproofability (is this a word?) I tried a search on Google referring to waterproof closed cell and could only find water resistant references.

George

 

[heaterman]

Sorry, I confused thermopex and microflex as being equal, maybe they aren't.

Now that you mention it, I don't think my dealer specified brand name, only TYPE of product. If Garn sells Microflex probably that's what he meant. He agrees with you though, as does Garn, that a couple of pieces of pex wrapped in a quarter inch of bubble/foil/insulation, stuck loosely into a length of flexible drain pipe is no good.

But he also said that Garn was leery of the closed cell urethane spray foam taking on moisture, over time.

I have contacted an insulation company that claims to have a product that WON'T take on water, however.

The microflex type product seems the safest bet to me, at the moment, I guess

Hi Rick, I had the same experience with Paul at Garn, he recommended Microflex, saying he was concerned with the foam absorbing moisture over time.

I do like the idea of the foam in trench and being new to this forum, respectively to others who use this method, question the application of the foamed trench if I cannot find documentation. It do like the additional insulation qualities and the reduced cost of the foamed in trench. However I would hate to find out that in 5-10 years I was dumping my heat into the ground because the foam became saturated and lost its insulation capability.

I now have a call in to the insulators for documentation on waterproofability (is this a word?) I tried a search on Google referring to waterproof closed cell and could only find water resistant references.

George

When we started using this method, I was leary of the water issue and also just general degradation of the foam over time. The insulating contractor that I was dealing with gave me the name of the factory (which escapes me right now) and I called and spoke with a guy in their tech department. He stated that their particular product was very suitable for the use I intended and the product life was almost infinite when buried. Sunlight will "dissolve" it over time but it is fully tested and rated for direct earth contact.

I would do a little research starting with the insulating company that you intend to use and ask them if they have a tech number you can call. They should be able to put you on the right track.

 

[Sawyer]

Hi Rick, I had the same experience with Paul at Garn, he recommended Microflex, saying he was concerned with the foam absorbing moisture over time.

I do like the idea of the foam in trench and being new to this forum, respectively to others who use this method, question the application of the foamed trench if I cannot find documentation. It do like the additional insulation qualities and the reduced cost of the foamed in trench. However I would hate to find out that in 5-10 years I was dumping my heat into the ground because the foam became saturated and lost its insulation capability.

I now have a call in to the insulators for documentation on waterproofability (is this a word?) I tried a search on Google referring to waterproof closed cell and could only find water resistant references.

George

When we started using this method, I was leary of the water issue and also just general degradation of the foam over time. The insulating contractor that I was dealing with gave me the name of the factory (which escapes me right now) and I called and spoke with a guy in their tech department. He stated that their particular product was very suitable for the use I intended and the product life was almost infinite when buried. Sunlight will "dissolve" it over time but it is fully tested and rated for direct earth contact.

I would do a little research starting with the insulating company that you intend to use and ask them if they have a tech number you can call. They should be able to put you on the right track.

Thanks for the suggestion Heaterman, I just talk with Corbond as you suggested and they will have their service rep call me today or tomorrow. The lady in customer service did say that she feels that no one would say the closed cell foam is water proof but Neil would discuss the permiability of the foam and that would assure me of the quality of the product for my underground application. Another problem I will have is the pipe has to be run under 100' of driveway so it will be installed within the frost zone. Do you know which product your installer uses?

 

[Sawyer]

I am now waiting for a call from Corbond and information from Heatlock. Heatlock's rep said he thought their product was perfect for this application, the reasoning went with the permeability of the product at 1.2" and the rep said that would be a good figure to use in underground applications to measure the performance of similar products. It should be noted that both manufactures reccomend their product for sealing basements in an underground application. One applicator stated that "even if the product were saturated it would not loose its insulation factor". I am nervous about this applicator unless I see this in writing from the manufacturer of his insulation product.

I will post when I get responses from the manufactures.

 

[Paul]

Thanks for the input on the differnet options. I think I am going to stick with a premade system -even if it cost more I will not have to dig it up if it becomes saturated. My installer has seen the foamed in trench application used and when it became saturated he measured huge heat loss. I will be passing my pipeing through a 10 inch culvert to protect it due to my shallow installation.