Replacing Copper Water Supply Line with PEX?

[jon v.]

I live in San Diego, CA, and I'd like to replace the water supply line between our water meter and house. The current setup is pretty simple: there's a 1" copper pipe covering the 20' span through the middle of the front yard in a straight line, and it doesn't pass under any hardscape. It's buried at a depth of 1 ft (no freezing here!). The pipe curves up at the end, where it connects to (in this order) a tee and ball valve feeding the irrigation system, a shutoff gate valve, a hose bib, and then heads into the house.

My wife and I are re-landscaping the yard and want to plant a tree in the center, right where the supply line currently passes. So, I'd like to install a replacement supply line which will curve around the tree zone (maybe with a radius of ~6 ft? We'll plant a tree with a root system that goes deep vs. spreading laterally, but I want to be sure to keep the pipe clear.). I'm fairly handy and want to do the work myself, if possible, but I also want to make sure I'm installing a robust system that makes sense technically and meets code. I've heard of people replacing their mains with PEX, and I'm tempted to go that route for its simplicity and smooth curves, but I don't know much about how the connections with the copper work or whether the pipe has to be installed with some sort of sleeve for protection. I wonder if folks can help me figure out which pieces to use (or point me to another post already answering this question), assuming I don't know much about this type of job. Also, I'm curious whether more experienced plumbers have recommendations about the order of valves next to the house--would you recommend having the shutoff gate valve positioned before the tee off to the irrigation system?

Thanks in advance for any advice, and all the best,
Jon

 

[CountryBumkin]

PEX is good stuff. Easy to work with and cheaper than copper. If you are replacing 1" copper you would go with 1-1/4" PEX to retain the same flow.
You need a copper-to-PEX fitting. Solder the fitting to the copper then crimp the PEX to it. There are different types of PEX (Type A is the best).
I would put the shutoff valve wherever it makes you life easiest (one at the entrance to the irrigation system for sure) so you can shutoff different sections of your plumbing to repair or work on it.
See this site for PEX info: http://www.supplyhouse.com/resources/pexPlumbing

I like the Uponor brand (AquaPEX) but this requires a special "expansion tool" (which is one of the main benefits of this line. Fool proof connections).

I'm not a pro.

 

[Sponsor]

 

[jon v.]

PEX is good stuff. Easy to work with and cheaper than copper. If you are replacing 1" copper you would go with 1-1/4" PEX to retain the same flow.
You need a copper-to-PEX fitting. Solder the fitting to the copper then crimp the PEX to it. There are different types of PEX (Type A is the best).
I would put the shutoff valve wherever it makes you life easiest (one at the entrance to the irrigation system for sure) so you can shutoff different sections of your plumbing to repair or work on it.
See this site for PEX info: http://www.supplyhouse.com/resources/pexPlumbing

I like the Uponor brand (AquaPEX) but this requires a special "expansion tool" (which is one of the main benefits of this line. Fool proof connections).

I'm not a pro.

Thanks for your tips, Mike! I had a plumber tell me yesterday that he wouldn't recommend going for PEX over copper, but it wasn't clear to me what the downsides would be. Do you have any advice about the need to install the buried PEX in a sleeve, or protecting it somehow in the ground?

Thanks again,
Jon

 

[Dj2]

PEX never gained popularity in CA, so far. In fact it was only recently been approved in LA county.

Could be the fact that in many communities, especially near hills and mountains, street water pressure is high. Could be other reasons.

What you want to achieve, bypass the area where you want to plant a tree, can be done with copper pipes, elbows, 45s and couplings.

Talk to more plumbers, you'll get similar answers.

If it were my home, I would stay with copper.

 

[Zimm0who0net]

Here in AZ I've seen plumbers put in PEX 1' down without any sleeve. PEX is technically not allowed if it's exposed so the riser to the house is typically something else, but I've seen plumbers put PEX there too and just shield it in a piece of electrical PVC (but I'd guess that isn't allowed by code). That said, I personally think it's a bit unwise to put a PEX line just 1' down without any protection. I'd put it in a PVC sleeve. Oh, and while you're at it don't forget to attach a tracer wire so you can locate it in the future. Go to a supply house and get the real tracer wire. Don't just get the THHN roll from home depot.

Finally, check how your electric system is grounded. Many houses use the copper main service line as their electric panel grounding. If you replace it with PEX, you'll have to drive a couple grounding rods 8' down to replace the grounding.

 

[jon v.]

PEX never gained popularity in CA, so far. In fact it was only recently been approved in LA county.

Could be the fact that in many communities, especially near hills and mountains, street water pressure is high. Could be other reasons.

What you want to achieve, bypass the area where you want to plant a tree, can be done with copper pipes, elbows, 45s and couplings.

Talk to more plumbers, you'll get similar answers.

If it were my home, I would stay with copper.

Thanks, dj2. Are there any concerns with burying a number of copper joints, in terms of the lifespan or structural integrity of the run? I originally liked the idea of either using soft copper or PEX to avoid joints in the middle of the run, but using a few 10' hard copper pipes and elbows would certainly be more cost effective than buying a 60' roll of 1" copper or 1 1/4" PEX for this small project.

 

[jon v.]

Here in AZ I've seen plumbers put in PEX 1' down without any sleeve. PEX is technically not allowed if it's exposed so the riser to the house is typically something else, but I've seen plumbers put PEX there too and just shield it in a piece of electrical PVC (but I'd guess that isn't allowed by code). That said, I personally think it's a bit unwise to put a PEX line just 1' down without any protection. I'd put it in a PVC sleeve. Oh, and while you're at it don't forget to attach a tracer wire so you can locate it in the future. Go to a supply house and get the real tracer wire. Don't just get the THHN roll from home depot.

Finally, check how your electric system is grounded. Many houses use the copper main service line as their electric panel grounding. If you replace it with PEX, you'll have to drive a couple grounding rods 8' down to replace the grounding.

Thanks for the good advice, zimm0who0net. It sounds like some of the simplicity I've associated with PEX when used indoors may not hold when it's used outdoors and underground.

 

[Reach4]

I originally liked the idea of either using soft copper or PEX to avoid joints in the middle of the run, but using a few 10' hard copper pipes and elbows would certainly be more cost effective

Some places require type K (green ink) copper. If you have been pricing M or L copper and need to switch to K, it will cost more than you were thinking. The rules vary. https://terrylove.com/forums/index.php?threads/burying-copper-pipe.40707/

http://www.iapmo.org/Documents/Codes/2010 California Plumbing Code PEX Emergency Supplement.pdf says type L, as well as K, is OK underground. I don't know what the current rules are.

 

[Dj2]

Thanks, dj2. Are there any concerns with burying a number of copper joints, in terms of the lifespan or structural integrity of the run? I originally liked the idea of either using soft copper or PEX to avoid joints in the middle of the run, but using a few 10' hard copper pipes and elbows would certainly be more cost effective than buying a 60' roll of 1" copper or 1 1/4" PEX for this small project.

Done correctly, there is no problem with multiple joints. Use Type L copper, lay it down on 1"-2" of sand, cover with 1"-2" sand.

 

[jon v.]

Some places require type K (green ink) copper. If you have been pricing M or L copper and need to switch to K, it will cost more than you were thinking. The rules vary. https://terrylove.com/forums/index.php?threads/burying-copper-pipe.40707/

http://www.iapmo.org/Documents/Codes/2010 California Plumbing Code PEX Emergency Supplement.pdf says type L, as well as K, is OK underground. I don't know what the current rules are.

Thanks for the documentation, Reach4. It looks like L is just fine here.

 

[jon v.]

Done correctly, there is no problem with multiple joints. Use Type L copper, lay it down on 1"-2" of sand, cover with 1"-2" sand.

Thanks, dj2. Will I notice any drop in pressure due to the energy losses across the four 45 elbows, or will those be pretty negligible?

 

[Dj2]

Thanks, dj2. Will I notice any drop in pressure due to the energy losses across the four 45 elbows, or will those be pretty negligible?

You most likely won't feel the difference.

 

[jon v.]

Done correctly, there is no problem with multiple joints. Use Type L copper, lay it down on 1"-2" of sand, cover with 1"-2" sand.

Hi guys. Thanks again to everyone for your input--hopefully these will be the last questions before taking this project on:

I've heard a few plumbers recommend plastic sleeving for buried copper pipes in our area, to provide protection from both mechanical forces and our corrosive soils. Assuming I go with a run made using 1", hard, Type-L pipe connected with 45 degree fittings,

1) What type of pipe sleeving should I use? I've seen people use either the brightly-colored flexible stuff that comes in a roll or schedule 40 PVC. It seems like the PVC would perhaps provide more structural protection than the roll stuff, but also leave room for water to get trapped between the pipes if not sealed properly.
2) How would the sleeving (either type) work with the 45-degree joints, and how would you solder the last pipe connection without melting the sleeving, assuming it will already be in place at that point?
3) If the copper run currently serves as the electrical ground for the house, how do I install sleeving while preserving that function?

 

[Plumber69]

Are you planning on soldering or silver soldering these joints

 

[jon v.]

Are you planning on soldering or silver soldering these joints

I'm planning on soldering.

 

[Jason Bold]

If anyone's still interested in this, here's a simple video of the process of changing from Copper to PEX

And here's another on the types of PEX you can buy