Updating water lines

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beulahyp

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Hello all,

my family and I just moved into a 1920’s home and one of the first things I want to do is update the water lines from copper to cpvc.

Our previous (and first) home was in the country with a well, and this house is in the city, so it’s our first experience with city water. The line that comes into the house is 3/4” but immediately Goes to the meter and transitions to 1/2”. My understanding has always been that 3/4” is better for water pressure, etc. but I want to be sure I’m in the right before replacing all the 1/2” with 3/4”. What would you all suggest? Would replacing everything with 3/4” just lead to water waste/longer wait times for hot water, or is the difference negligible?
 
Where are you living?
Your profile does not say.
That would help.

What is wrong with copper?

Yes, your existing copper is pretty small diameter.

Maybe you can create a 3/4 inch manifold to branch to 1/2 inch copper existing zones.

Why choose cpvc?

Why not 3/4 or better yet one inch pex, branching to 3/4 then some 1/2?

Because pex fittings reduce the inside diameter, one inch would give good pressure and be easier to run all over your house with less fittings.
 
Thanks for the replies!

We just moved to Lancaster, PA.

I do not know how to solder copper and cpvc is so easy to work with. Everyone I ever talked to indicated that cpvc is so much better than copper. This is the first I’m hearing otherwise. Copper requires using a torch and solder to work with and is pretty expensive to buy if you need to do work. cpvc is so inexpensive and simple to use. What is the benefit of copper over cpvc? I’ve never used pex before so maybe that is better?
 
I'd rather use PEX that CPVC, but given my choice, good ol' copper can't be beat. Get a few fittings, and a small stick of pipe, and practice using flux and a nice hand held map gas set up.
 
I would suggest you replace only the 1/2" lines that should be sized at 3/4", which generally speaking are those lines that would typically see higher flows due to feeding more fixtures. Once you branch off to one or maybe 2 fixtures, 1/2" may be fine. It all depends on flow requirements of the fixture(s). You definitely would not want to run 3/4" all the way to a bathroom sink or toilet but would want to use 3/4" feeding a bathroom group.
Of course if you have a very low pressure and/or you are running very long distances a 1/2", even with a small demand, could justify a 3/4' line. But typically based on plumbing codes, all typical residential plumbing fixtures only call for 1/2" BRANCH lines.

What kind of pressure do you currently have coming into the house?

Do you have areas and or fixtures where the pressure is definitely too low, particularly when you are running 2 or more fixtures at the same time.

The plumbing codes can help size water piping as they typically cover minimum requirements for different fixtures and combination of fixtures. It's not that difficult to follow but they do get into a few areas that can be confusing for people that are new at it.

For example, their sizing criteria typically uses WFU(water fixture units) instead of GPM since it also takes into consideration probability of things being used or not being used all at the same time. Good for larger buildings but overkill for residential applications. The method of probability should never be used for a small number of fixtures.
Sorry if I just confused you.
 
That is all very helpful, actually.

currently, there is only one bathroom, on the second floor, but we intend to add a master bathroom in the finished attic.

the shower currently doesn’t have any hot water pressure. I thought it was the cartridge, but upon removing it and running the water, the cold water pressure is still significantly better. So my assumption is a kink or clog in t he line somewhere. The sink has plenty of hot water pressure. I don’t want to buy a bunch of shark bite fittings and figured if I am going to replace a good bit of line to the shower, I might as well just start in the basement and run all new lines. Either way, I’ll need to get into t he plaster wall to access the piping.

Genuinely curious, what is the benefit of copper over cpvc or pex?
 
If your shower valve is newer, you might also have a pressure balancing module inside there, which could have gone bad.
Also, there may be a built in shutoff valve on the hot side of the shower valve, which might be partially closed.
It usually would have a flat screwdriver type slot.
The slot should be in line with the hot water pipe if fully open.
It will be perpendicular to the pipe if fully closed.

Meanwhile, pex is much easier to fish behind walls and between floors for whole-house replumbing.

Plastic pipe or copper will require much more cutting opening in walls and floors and ceilings.

If your water meter has 3/4 inch openings on both ends it is fine.
If it is 1/2 inch it should be replaced, it is a choke point for good flow volume.

Cpvc is supposedly very brittle when cold, and will also burst more easily than copper.
Pex supposedly is more tolerant of freezing, but the crimp rings can expand and leak when the pipe thaws.
I have read that the cinch-type rings are more reliable in areas that are at risk of freezing.
Just what I have read.
 
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In answer to your question, "Would replacing everything with 3/4” just lead to water waste/longer wait times for hot water, or is the difference negligible?"

It would use approximately twice the amount of water and take approximately twice as long, assuming the same flow rate.

See the contents of Type L copper piping in the following chart.
https://www.hotwaterproducts.com/service/pipevolumecalculator.html
 
A very common residential water meter size is 5/8" x 3/4".
A 5/8" x 3/4" water meter has a 5/8" water flow capacity just like a 5/8" meter.
Not a substantial difference in pressure loss between the a 5/8 and a 3/4. Unlike a long pipeline.
Typ Press Loss thru Water Meters.jpg
 
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The shower head is pretty old. It doesn’t even have a cartridge. After disassembling, it seemed to be in good shape.

I’m not home at the moment but I believe the meter is 1/2”. Here’s a pic I took but can’t tell if it shows in it.
 

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Not the shower head, the shower valve in the wall.
It might have a built in stop valve which is partially closed.

Or a pressure balancing unit that is malfunctioning.
 
No more than two fixtures to be served by a 1/2 water line. Consult the wsfu for your state.
 
Ask your village or water provider if you can upgrade to a 3/4 inch meter.
Unless pros on here think that is not needed.

Tell them you think it is broken, they will race over there, to get every penny they can squeeze out of you for their water.

Tell them, “Sometimes, the needles don’t spin while water is running. Is that ok?”

Every little bit of pipe restriction adds up.
 
Ask your village or water provider if you can upgrade to a 3/4 inch meter.
Unless pros on here think that is not needed.

Tell them you think it is broken, they will race over there, to get every penny they can squeeze out of you for their water.

Tell them, “Sometimes, the needles don’t spin while water is running. Is that ok?”

Every little bit of pipe restriction adds up.
I'm no pro...but not needed. In my opinion.
Neptune T-10 water meter.jpg
 
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