Burying pex

[curtis]

I am going to be digging my trench to bury the insulated pex I have for my garn tomorrow. The company says to bury it below the frost line to minimize any movement in the ground. The frost line where I'm at is 48" deep, do you guys think it's necessary to go that deep?

Side note for anyone thinking about using this stuff. Do it in the summer when it's warm out. Holy smokes is this stuff stiff. Hopefully tomorrow's 55 and sunny forecast is right and I can muscle it into the trench alright.

 

[OH_Varmntr]

Mine is buried 18", our frost line is supposed to be ~36" around here.

The summer doesn't help much at all. Atleast with ThermoPex. The insulation is what makes that stuff stiff.

 

[Cornell3786]

Buried mine about 24-30" had to make three pretty gnarly bends, one under the garage footing one under a sidewalk and then a 180* bend to get it in my block going to my basement. Did it in the summer and it sucked. It was pex al pex talk about stiff.

Get someone to help you or it'll eat your lunch

 

[Cornell3786]

Buried mine about 24-30" had to make three pretty gnarly bends, one under the garage footing one under a sidewalk and then a 180* bend to get it in my block going to my basement. Did it in the summer and it sucked. It was pex al pex talk about stiff.

Get someone to help you or it'll eat your lunch

Even triple insulated pex al pex in conduit melts snow in the winter when I brought it into my basement it was only about 10" under the garden.

Keep the pump running and it'll never freeze

 

[Coal Reaper]

I did non-al pex in may and it sucked. Even left it lauing straight on the driveway for a week. I was up til 3am the night before spray foam guy came. My trench was 24" min at bottom.

 

[flyingcow]

If you have the ability to go that deep I would. But i couldn't. It starts out 16 inches below grade and goes down to 4ft once it enters the house. It wasn't a long run, maybe 40ft from building to building? I put 2 ft wide 2 inch thick sheet foam just below the grade. Normally frost will only go straight down. Also I used thermopex. Damn hard to bend any at all. But i have 15ft of it exposed in my garage, put your hand on it and there is no heat, seems to be insulated well.

 

[curtis]

I can go down 48" for most of it if I had too. I have the Rehau brand pex which I'm sure is similar to the thermopex. Maybe where I can't go down that far I will lay a sheet of insulation board on top of it. I'll let you guys know how it goes, brother is coming over to help so hopefully it goes smooth.

 

[heaterman]

Better round up a few 6 packs and some buddies Curtis. Might even have to put some brats or burgers on the grill.
Maybe the local football team out for pizza's..... Or maybe tie that dog of yours to one end. She'd be a good anchor.

It will be impossible with one guy.

 

[curtis]

Haha I hear you there Steve! I managed to get one end held down by putting it through the center of a old truck rim and tire I had. I think if I have my brother back fill the hole as we go it will work. Do you think. 30" down will be fine? As I get close to the house it won't be as deep though.

 

[Medman]

I don't know exactly where in N. MI you are, but I'm in the Soo and I went down 4-5 feet over the 140 foot run I have. I had a local excavation contractor do the dig and the fill-in for $400 cash. I installed the insulated pex myself in October, just around freezing. I had to get my kids to stand on the line while I unrolled it!
I'm seeing about 1 *F drop in temp over 140 ft at 4-5 gpm. I would hesitate to go shallower due to the potential heat loss from the lines.

 

[flyingcow]

Took 3 of us to handle a 60ft piece. I had it laid out for close to a week in my truck garage, with all kinds of weights on it to straighten it out. Carried it 300ft from my truck garage to the house. By the time we got it to the house, the thermo pex curled right back up. Should of had it on video, quite comical, later. At the time there was a bit of grumbling going on. I can see why Heaterman is a fan of running the bare pex and having a foaming contractor foam it in place.

 

[heaterman]

We seldom go more than 30* deep unless we have to go under an area where there is going to be traffic on top of the tube, like a driveway.
One that we did went across a drive on a farm and due to an old footing/floor buried under the drive we could only get about 24-28" down.
We put blue board under it and alongside the tube, had it sprayed in place, then filled the "box" with sand to the level of the sides and capped it with another piece of 2" blueboard. There is never a trace of thawing in the drive even though it has 80,000 pound equipment (think 6,000 gallon manure spreaders...) driving over it.

Lot's of times in our area we have to stay as little as 18-20" deep to keep out of the water table. That is something to avoid at all costs.

 

[curtis]

We seldom go more than 30* deep unless we have to go under an area where there is going to be traffic on top of the tube, like a driveway.
One that we did went across a drive on a farm and due to an old footing/floor buried under the drive we could only get about 24-28" down.
We put blue board under it and alongside the tube, had it sprayed in place, then filled the "box" with sand to the level of the sides and capped it with another piece of 2" blueboard. There is never a trace of thawing in the drive even though it has 80,000 pound equipment (think 6,000 gallon manure spreaders...) driving over it.

Lot's of times in our area we have to stay as little as 18-20" deep to keep out of the water table. That is something to avoid at all costs.

I got it dug out to around 48" for the most part and the last 10' to the house it's around 24"-30" so I think I should be ok. Lots and lots of sand in my yard made the digging easy with the little excavator I rented.

 

[Fred61]

Lucky dawg. Sand is a poor conductor of heat as opposed to heavy clay like soils. It's always much warmer if it is above the water table.

 

[eauzonedan]

Curtis
That sand is your friend. The reason the roads up here in northern cheese land hold up so well is due to it. Sand won't hold the moisture and freezing and thawing doesn't make it move around like clays. Jetting it with water is a also a neat trick if you want to compact a driveway crossing. Your depths should be fine
Dan

 

[curtis]

Wow that wasn't fun in the least bit! Got It buried though and ran through a nice hole in the basement wall courtesy of my sledge hammer. When I was trying to bend it in through the basement wall it didn't seem to want to bend and just started kinda folding the outer black shell. It's not kinked bad and I'm thinking it was just the insulation not the actual pex. Do you guys think that may be a problem? It was bending it the opposite way that it naturally curled and it's not even a tight bend at all.

 

[B-Mod]

Push a slightly smaller pipe inside the pex if you can till you are past the kink part, then you will know if it is kinked or not.

 

[curtis]

Good idea, I'll try that tomorrow.

 

[Lapeer20m]

I opted to run my pex the 18 feet from boiler to house above ground inside an 18inch diameter plastic culvert insulated to a value of at least r40. Plus the pex is wrapped in armor flex.

Mine won't be below the frost line but it is an acceptable risk.

While this solution won't work for everyone it is ideal for my setup.