Trenching water lines pex vs. poly vs.soil with no rock vs. lots of rocks

[Fesntkilr]

I am gearing up for a winter project to run some water lines underground back to our garden. The run is about 200 feet and we live on bottom land soil with very few rocks. Then when I am finished I am going to trailer rented machine and go trench some water lines up at our deer property, that soil is very rocky.

Here are my questions:

Would a mini excavator be better than a walk behind trencher for both rocky and non rocky soil? It seems a trencher is faster in non rocky soil but a mini X can pull some rather large rocks out of the way.

Black poly seems to be material of choice for underground water lines, yes? 30" is code burial depth here. From my rental property days (that are thankfully over) I have lots of experience with Uponer/Wirsbo pex and also have the Milwaukee cordless Uponer tool and lots of fittings from 3/4" to 1"

What is a suitable backfill material? Sand?

Any recommendations on a good brand of frost proof hydrants? I hope to find something American made.

Can anyone tell me where to find a cutaway schematic on the gravel/sleeve/concrete slab detail of running a frost proof hydrant into a small concrete slab?

Any general cautions or sage words of wisdom?

Thanks in advance!

 

[Sledgie]

I attached the frost free spigot to a pounded in metal fence post then centered it in a 4x4 concrete slab to keep the mud down. It worked well for about 7 years then started leaking underground. No way to fix it without tearing up the concrete, so dug down where the line went under the concrete and just put in a new hydrant fastened to the side of the slab with a couple of conduit clamps and concrete screws. It faces toward the middle of the concrete so looks fairly well like it was planned. I cut the old hydrant and fence post off flush with the concrete. So I guess my advice would be not to center the hydrant in a slab if you ever have to work on it. Also, my experience with trenchers say they are helpless in soil with rocks any bigger than your fist. Also, use brass or plastic fittings at the bottom to adapt to your tubing, as galvanized will fail sooner or later since it is in damp soil all the time ( In my case 7 years).

 

[Fesntkilr]

Great advice on not using galvanized. Did yours fail within 7 years? I was thinking to sleeve a 2 or 3' PVC pipe down to the 90 joint in the water supply line and pour concrete around PVC sleeve. The spigot would then fit loosely inside that sleeve. The PVC sleeve would be notched to actually cover the 90 degree fitting, similar to a residential curbside water supply shutoff access tube. If I were to use a threaded 90 degree and the spigot is threaded, I could ***in theory*** un-thread spigot for repair without disturbing slab. Spray some foam down the PVC sleeve hole and seal it with a commercial Sonneborn type urethane sealant (caulk) and it would make the spigot solid, firm AND fully serviceable by simply cutting away the urethane seal and carefully un-threading spigot.

OR

Screw all that and just pour gravel instead of concrete

 

[Fesntkilr]

Flint Hills? Up around Manhattan/JC area?

 

[bcp]

About a year and a half ago I replaced a leaking frost-free hydrant for a neighbor. It was in the center of about a yard square concrete pad. The leak was the tee broken on both sides and lifted. I'm guessing wet soil under the slab froze and lifted the hydrant, breaking the pvc on each side of the tee.

Bruce

 

[ajmaxham]

Do not use the 100 psi black poly. The 200 psi black poly would be a good choice but will cost more than the 160 psi black poly. Set pipe in sand or rock free soil.

 

[Fesntkilr]

Thanks for the reply. I am wondering if I would need to go to a plumbing supply house in the city to find 200psi poly or do the run-of-the-mill Tractor Supply, Orscheln's, Farm n Fleet (et al) type stores usually carry it?

 

[ajmaxham]

I attached the frost free spigot to a pounded in metal fence post then centered it in a 4x4 concrete slab to keep the mud down. It worked well for about 7 years then started leaking underground. No way to fix it without tearing up the concrete, so dug down where the line went under the concrete and just put in a new hydrant fastened to the side of the slab with a couple of conduit clamps and concrete screws. It faces toward the middle of the concrete so looks fairly well like it was planned. I cut the old hydrant and fence post off flush with the concrete. So I guess my advice would be not to center the hydrant in a slab if you ever have to work on it. Also, my experience with trenchers say they are helpless in soil with rocks any bigger than your fist. Also, use brass or plastic fittings at the bottom to adapt to your tubing, as galvanized will fail sooner or later since it is in damp soil all the time ( In my case 7 years).

Use brass fittings - plastic fittings will also fail.

 

[ajmaxham]

FYI the id of the 200 psi pipe is smaller than the id of the 160 psi pipe. I think you will need to go to a plumbing supply house for the 200 psi pipe and fittings.

 

[gzfrt9]

I just put in 600 feet of black 200 psi water line last weekend. We rented a Bobcat T650 with a trencher. Almost 5 foot stick.
It worked fantastic. However, we have all red sand. So the only problem is how fast can you put pipe in ground before is caves.

Makes me want to own the machine!