Replacing underground main line - questions about pex

dwoloz

Hi all

I'm looking to replace my galvy 1/2" water main line with either 1" soft copper or pex. I'm leaning towards the pex because of the cost saving. Pex was just approved last year in California and being new here, I haven't seen any examples to learn from so Im flying in the dark a little

Our water meter is in the sidewalk and the main line currently runs underground 15ft, goes to the surface right before the foundation where there is a shut off valve, then goes through the wall into the crawlspace. (It should be noted it doesn't freeze in this climate)

Since pex is UV sensitive, Id obviously not want to daylight it like the current setup. Id rather want to run it underneath the foundation into the crawlspace, yes? If so, where would I plumb in a shut off valve? There unfortunately does not appear to be enough room in the meter box to put one in.

Also, would you recommend running the pex sleeved in something like ABS for the underground run?



Thanks in advance for your advice

Homerepairguy

I would run copper under ground from the meter to the shut off valve and after the valve into the crawl space. Copper would provide the strength to support the valve and, being exposed to sunlight, would not have any UV on PEX issues. Just be sure to use copper approved for burial.

If you don't have a pressure regulator, I would install one right after the valve outside of the house, then go into the crawl space. Once inside of the crawl space, I would switch to PEX for the house plumbing.

One other thing to consider. I have an outside water faucet between the shut off ball valve and the pressure regulator. Since our city water pressure is about 120 psi, I can use that pressure to clean the sidewalk along side our house, clean the trash pickup bin, and various other pressure cleaning chores. Our pressure regulator brings the pressure down to 60 psi for the house.

HRG

VIPlumber

Pex can be run underground (I prefer copper as well) but make sure that there are no sharp edged rocks in the trench and surround it with sand, ~ 12". Make it is run in one continuous length with no underground joints.

As for entry into the crawlspace, if the floor is concrete then make sure it is sleeved in ABS. If not, then disregard.

I'd place the shutoff in the crawlspace so no one can mess with it easily, except you. Once inside the order of assembly would be shutoff then 'Pressure regulator' (proper name is Pressure Reducing Valve - PRV). For the shutoff I'd a use a stop & drain. That way you could drain the entire system from the shutoff, if need be.

dwoloz

Hm, ok, so perhaps copper is best here. I hadn't considered a pressure regulator, I'll look into that

I actually would like to make the shut off as easy to access as possible. I have several people who live with me and in the case of emergency, Id like it to be very easy for them to quickly shut off the water.

VIPlumber

A PRV is only necessary if the water pressure coming into the house is greater than 80 psi. You could bring the shutoff & PRV into a central closet for easier access.