Forums:

Has anyone here worked with insulated underground PEX pipe for water lines or heating projects?

Posts: 1

posted 3 weeks ago

6
Number of slices to send:

Optional 'thank-you' note:

Send

Hey everyone,

I’m looking into it for a property upgrade and wanted to hear real‑world experiences rather than product pitches.

A few things I’m curious about:

installation challenges you ran into

how it held up over time in different soil or climate conditions

any tips you wish you knew before starting

alternatives you’ve tried and how they compared in your situation

Not trying to promote anything—just hoping to learn from people who’ve actually used it. Always appreciate hearing what worked, what didn’t, and what you’d do differently next time.

Tyler Grace

Posts: 81

Location: Colorado Springs, CO [Zone: 5B/6A]

I like...

posted 3 weeks ago

4
Number of slices to send:

Optional 'thank-you' note:

Send

What are you trying to do specifically? Indoor and/or outdoor project?

Pex is pretty unstable outdoors, UV rays cause it to degrade. It's mostly used for indoor plumbing. I guess if you were to insulate it, it would protect it but it seems like extra work when you could just use polyethylene pipe in an outdoor setting. Use copper stubbed outside of your house to connect to it, not pex.

I don't know exactly what you're trying to achieve but, generally speaking, use poly pipe outdoors and pex indoors.

"Irrigation is not something that you just dump something on. It's not a big truck. It's a series of tubes."

John F Dean

master steward

Posts: 8032

Location: southern Illinois, USA

3035

I like...

posted 3 weeks ago

1
Number of slices to send:

Optional 'thank-you' note:

Send

I have only worked indoors with it. It seems to do well. I have heard that underground it is attractive to mice, etc.

I want to be 15 again …so I can ruin my life differently.

Martin Mikulcik

Posts: 52

Location: Missouri

posted 3 weeks ago

4
Number of slices to send:

Optional 'thank-you' note:

Send

Just run normal pex underground, the insulation does nothing because there's nothing heating it. Like insulating an unheated shop. (It may protect it from heating cooling cycles/vibrations sanding the pipe through) I'm not sure that's ever even happened but then use a pvc sleeve so you can pull a new pipe through later like they do electric.

Obviously it must be below the frost line. Around here that's 2ft and at that depth rodents aren't a problem. Can't speak for extremely shallow installation

Don't bury any connections. That's important.

Use (pex a) like uponor if you're extra paranoid

Martin
Flyoverseeds.com

Aaron Yarbrough

gardener

Posts: 335

Location: Austin, Texas

155

I like...

posted 3 weeks ago

4
Number of slices to send:

Optional 'thank-you' note:

Send

Both below and above ground I like to insulate the hot water line especially on long runs. PEX will shed a lot of heat.

I second Martin's suggestion not to bury any connections.

My suburban building and homesteading blog https://offgridburbia.com/

C. Letellier

pollinator

Posts: 1131

Location: Greybull WY north central WY zone 4 bordering on 3

343

I like...

posted 3 weeks ago

3
Number of slices to send:

Optional 'thank-you' note:

Send

Normal procedure is encase the insulation and PEX in an external conduit to protect the assembly. So mice and external weather are less of a problem. Being properly buried reduces it even more.

Only one I know of, as a problem was fiberglass wrap installed in PVC conduit around PEX. Their mistake was aiming both ends up and it gathered moisture so the insulation failed. So if you use a permeable insulation be sure the pipe is sloped so it can drain and stay dry. Can't help otherwise.

Country oriented nerd with primary interests in alternate energy in particular solar. Dabble in gardening, trees, cob, soil building and a host of others.

R Scott

pollinator

Posts: 4201

Location: Tennessee 7b

343

posted 3 weeks ago

Number of slices to send:

Optional 'thank-you' note:

Send

I’ve installed the boiler style-hot and cold both pre-run through a single corrugated drain tile. It is easy to install…until you need to go into an existing foundation. It doesn’t have much insulation between the hot and cold lines so you bleed a fair bit of heat to the return line but at least it isn’t lost to the dirt.

I have also helped with home-brew fixes when rock prevented burying deep enough for a short stretch. None of those solutions are anything I would want to do for more than 20 feet or so.

"You must be the change you want to see in the world." "First they ignore you, then they laugh at you, then they fight you, then you win." --Mahatma Gandhi
"Preach the Gospel always, and if necessary, use words." --Francis of Assisi.
"Family farms work when the whole family works the farm." -- Adam Klaus

craig howard

pollinator

Posts: 447

Location: zone 5-5

153

posted 2 weeks ago

Number of slices to send:

Optional 'thank-you' note:

Send

Some people think PEX won't break if it freezes.
But I had some break on top of the ground, and it has broken underground in our town when it froze.

Off topic a bit but I'd run 1/4" PEX next to the line so if it ever did freeze I could hook it up to my car and pump hot antifreeze through it.
It just sucks when the water line freezes. Often have to wait until spring and the ground thaws down to the pipe (mine is at 7 feet) to get water flowing again and to see if it broke.

Snow on the ground will help insulate it. Our pipes freeze under the street, but only if it is covered in a solid layer of ice.

I can't beleive you just said that. Now I need to calm down with this tiny ad:

Learn Permaculture through a little hard work

https://wheaton-labs.com/bootcamp