I have 2" PVC coming from my well, connecting to a PVC shutoff valve and then to an existing spigot. I want to removed existing spigot and extend water line 140ft to my RV location and install a hydrant style spigot.

Can I use 3/4 or 1" PEX piping underground?

  • Please ask one question per post. Your question about backflow prevention is unrelated to the first question about burying pex.
    – isherwood
    Jun 24 '21 at 16:08


Opt for PEX-B per https://homeefficiencyguide.com/can-pex-tubing-be-buried/

Make sure to protect brass fittings and metal crimp rings from the soil with a silicone wrap or just lather them in silicone from a caulk gun and let it cure before burying.

PEX's primary enemy is UV light so make sure to protect it if it exits the earth to supply the spigot.

  • Direct burial exposes the PEX to damage from burrowing animals: gophers, moles, rats, mice, etc. I have been told that these animals will not chew into PVC. If the expense of conduit is too much for your budget maybe just use glued PVC to carry the water Jun 24 '21 at 22:19
  • @monkeyzeus - What is the silicone wrap you mentioned?
    – Dean
    Jun 25 '21 at 14:21
  • @Dean See my edit.
    – MonkeyZeus
    Jun 28 '21 at 17:17
  • Why would animals "not chew into PVC" exactly? Just wait until you hear about polyethylene gas pipe!
    – MonkeyZeus
    Jun 28 '21 at 19:16
  • Does color matter? I guess since its cold water I can use blue or white
    – Dean
    Jun 29 '21 at 23:57

Best practice would be lay PVC as conduit and put the PEX inside it. Any bends would be Schedule 80 sweep 90s. You could use Sch 40 for the straight sections or use Sch 80 entirely. You would have to find out which size to use.

One plumber of my acquaintance advocated using polybutylene (PB) which comes on rolls. He also said chewing animals will not chew into PVC.

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