Water Supply Line questions

[RedMonte85]

I am going to be tapping in to a city water line that is about 300 ft. from my house. Copper used to be the go to for this sort of thing but now it seems PEX is way more cost efficient. Will PEX hold up over time being put in the ground? Is PEX the best thing to use for this besides copper?

Also, what size PEX tubing should I be using? 1" would seem too small to me since the inside diameter of PEX is slightly smaller than copper tubing. The house is 1600sq ft with another 1000 sq ft basement. 3 Full bathrooms and the house will be using hydronic heating. Can the pex be buried directly over dirt or should I be putting some sand down in the trench? It will be 5 feet deep in the ground.

Thanks

 

[Cacher_Chick]

Potable water rated HDPE is more common here. 3 baths at 300, then consider the potential for irrigation when sizing.

 

[Sponsor]

 

[Reach4]

http://www.charlottepipe.com/Documents/PL_Tech_Man/ExpansionandContraction.pdf talks of thermal effects, mainly on PVC. However the snaking described on page "57" (second page of 3 in that PDF) would apply to HDPE (AKA poly). Usually the kind that would be used is SIDR, which in effect means that the ID is suitable for standard barbs, with the pipe secured with a pair of worm gear clamps. SIDR pipe, for a given nominal size (such as "1 inch") is much larger inside than PEX. If you use PEX, you could upsize to the next nominal size. PEX is certainly good too. For long runs, the SIDR HDPE is going to be less expensive usually.

https://plasticpipe.org/pdf/mid-pe-field-manual-municipal-water-applications.pdf page 17 of 88 illustrates this, although that document is mainly aimed at cities rather than homeowners.

https://terrylove.com/forums/index.php?threads/tips-for-400-ft-pipe-run.74073/
https://terrylove.com/forums/index.php?threads/new-water-line-1000-feet-long.73241/
have some links and discussions. Note the Menards link.

https://www.huduser.gov/portal/publications/pex_design_guide.pdf page 79 talks of PEX, but it would apply to other poly. It says

Trench Preparation
Trench bottom shall be solid with no hollows, lumps, rocks, or other materials that could
damage the tubing.
Laying the Tubing
Tubing should be laid with sufficient slack (snaking) to accommodate any contraction due to cooling prior to backfilling. Tubing will expand or contract approximately 1 inch in length for each 10°F change in tubing temperature for each 100 feet of tubing.

Minimum bending radius requirements for PEX tubing shall be followed. See “Bending the
Tubing” Table.

Inspect tubing for damage. Remove and replace damaged sections.

In poor soil conditions, such as mud, rock, black gumbo, or clay, it is necessary to excavate
deeper and use good clean fill or granular fill to smooth the trench bottom.​

 

[Michael Young]

I am going to be tapping in to a city water line that is about 300 ft. from my house. Copper used to be the go to for this sort of thing but now it seems PEX is way more cost efficient. Will PEX hold up over time being put in the ground? Is PEX the best thing to use for this besides copper?

Also, what size PEX tubing should I be using? 1" would seem too small to me since the inside diameter of PEX is slightly smaller than copper tubing. The house is 1600sq ft with another 1000 sq ft basement. 3 Full bathrooms and the house will be using hydronic heating. Can the pex be buried directly over dirt or should I be putting some sand down in the trench? It will be 5 feet deep in the ground.

Thanks

Your frostline is 42". So you can save yourself a little digging; you don't have to go 5-feet.
Yes. Pex is rated for underground, so you can throw it in there and forget about it. But because you're so deep, you may want to install 1-1/2 black well pipe and use that as a sleeve for your 1" Pex. your pex by the foot, or buy a full 500-foot roll. NO JOINTS underground. Pull your pex out and cut about 320-feet of it. Leave it (and your sleeve) laying in the sun. Let the sun warm up that pipe. Now use heavy duty fishing line (3000lb test) to pull the 1" pex through the 1-1/2" black well pipe. Then drag the whole thing and shove the one side through your hole so the house side goes all the way through. Go ahead and CONNECT that side to the indoor plumbing and get out from under that house. You're done.

out at the meter, cut it to fit and connect the other end to the tailpiece on the meter. Use a sweat adapter at the tailpiece off te meter (or use a pro-press). DO NOT use a sharkbite fitting underground.