Which PEX sizes according to ...

[Bob NH]

If you wanted to use home runs you could simply make up an assembly of tees; probably with 3/4" CPVC. You could probably get 3/4" tees with 1/2" branch outlets, install a 1/2" ball valve on each, and run the line to each service point.

The advantage of a manifold and home runs with PEX is that it eliminates a lot of connected tee fittings. Tee fittings are not a big cost or problem with CPVC so there is little to be gained with a manifold and home runs.

I would probably run a main line in the direction of the kitchen and bathroom and then branch off to the fixtures as required.

 

[Redwood]

If you wanted to use home runs you could simply make up an assembly of tees; probably with 3/4" CPVC. You could probably get 3/4" tees with 1/2" branch outlets, install a 1/2" ball valve on each, and run the line to each service point.

The advantage of a manifold and home runs with PEX is that it eliminates a lot of connected tee fittings. Tee fittings are not a big cost or problem with CPVC so there is little to be gained with a manifold and home runs.

I would probably run a main line in the direction of the kitchen and bathroom and then branch off to the fixtures as required.

The advantage of homerunning Pex is that there are no Tee connections?
It's debatable whether that is an advantage! PEX Tees are not very expensive!
The other advantage is that you don't have to know how to size pipes?
That can be learned!

The disadvantages of homerunning PEX:
Spagetti all over the place,,, Miles of it
Long waits for hot water at every fixture... Recirculation not possible!

I would if it were my house, size the pex properly and run it very similar to copper. A main feed branching off with Tee's with smaller lines to fixtures. In a larger home A La McMansion I may run larger feeds to mini manifolds for individual bathroom groups.

If I was going to go through all the trouble of cutting straight lengths of pipe, and elbowing around turns and making up joints like you have to do with CPVC... I'd just use copper!
Bob, How much do you pay for a single 1/2" CPVC X 1/2" MNPT Brass Adapter?
Those things arent cheap!

 

[Sponsor]

 

[diy-mark]

The disadvantages of homerunning PEX:
Spagetti all over the place,,, Miles of it
Long waits for hot water at every fixture... Recirculation not possible!

In my 500 sq ft cottage (my wife has corrected me and informed me it's 730 sq ft), there would not be miles of spaghetti. I'm a notorious over-killer ("Owner-Builder from Hell" according to the local code department) and my spaghetti would be very neat and orderly even though it would probably never be seen again by another human eye.

I would if it were my house, size the pex properly and run it very similar to copper. A main feed branching off with Tee's with smaller lines to fixtures.

It seems to me that this would be more expensive than CPVC and probably more trouble and time too. Don't forget, I'm going to be under the house in an 18" crawl space and I want to spend as little time as possible down there. Plus, PEX mechanical joints under the house strikes me as less reliable than glued CPVC joints. In my mind, every mechanical joint is a potential problem down the road regardless of how well it was done in the first place.

As far as time goes, it seems to me that stringing home runs with PEX would be the least time consuming under the house. CPVC would take longer and PEX with joints (crimping etc.) would take the longest, unless I'm mistaken about that.

If I was going to go through all the trouble of cutting straight lengths of pipe, and elbowing around turns and making up joints like you have to do with CPVC... I'd just use copper!

Out of the question! I know how to solder copper pipe, but I ain't doing it under the house in those conditions. Plus the time factor for that method would be the longest of all these options. At least for me it would, since I'm not going to be using a high-heat military flame thrower like I've seen some plumbers use.

Let me ask you a question: Do you have something in particular against the use of CPVC?

I'm in South Florida with city water. The PH is about 7 or 8. The water here is supposed to be some of the best in the country.

 

[Redwood]

The pricing is not even close! PEX wins Hands Down!

Have a look see here!
http://www.watts.com/pro/divisions/potablepexplumbing/learnabout/learnabout_cinchclamp.asp

Take a look at the methods, order a catalog and look at the pricing. The tool can be purchased for about $50. I can install a tee in a PEX line in about the time it takes to cut and glue one side of a CPVC tee. 2 people working together 1 above and 1 below could knock this job out in no time at all.

 

[diy-mark]

$ & ¢

The pricing is not even close! PEX wins Hands Down!

If I do branch and tee, that might be true. If I do manifold, probably not true.

Thanks for the link. I don't think Watts is sold in my area so I'd have to order from the catalog, which means I take a chance on not ordering everything I'll need the first time.

I see that Nibco PEX is sold by a place near me. Is Nibco any good?

And I'm still curious about what you have against CPVC.

 

[Redwood]

Nibco?
Have a look at this thread...
https://terrylove.com/forums/showthread.php?t=21075

CPVC...
Around here its the common choice of the hacker handyman.
I have seen some nice work done but it's a low percentage.
If you are going through the trouble of using a rigid pipe with all the fittings used to join sections an manuver aroung turns... My thoughts are just use copper.
The biggest thing around here is that it gets cold in the winter... Sometimes with a power outage... I don't know if you have ever seen a house freeze up with CPVC... Let me assure you it is not pretty!
In addition to that I believe it can become brittle with I have see it break when struck. I don't believe that it would have been a problem with either copper or, PEX

As far as the Watts PEX I would call around to supply houses to see if they have it in your area.

 

[Bob NH]

. . . And I'm still curious about what you have against CPVC.

CPVC is widely used in the chemical industry and has been accepted for residential use as well. Components are inexpensive and it requires no special tools.

A DIYer can do good work or lousy work with CPVC. It's in your control.

One of the problems that some pros have with CPVC is that it is easy for the non-pros to work with it. It takes away work if you can do it yourself.

http://www.rd.com/18255/article18255.html

If you are connecting to a metal system, such as copper, you need CPVC-to-metal transition fitting. The issue is usually that if you screw metal into plastic you may break the plastic female fitting. You can screw a CPVC male adapter into a copper female adapter. Most fixtures will adapt to a 1/2" male threaded part to that is not a problem. You can get 1/2" ball valves for shutoffs, threaded or socket.

If you are in an area subject to occasional freezing you can easily put in drains.

If you care about your work you can do as neat a job with CPVC as you can with copper. You will need more clamps to keep it from sagging but it is easier to run through holes in joists and studs.

 

[Jadnashua]

The tool isn't cheap (you can probably sell it afterwards, or maybe rent one), but Wirsbo is the easiest to install blind..No crimp rings to drop or not get the crimper on straight. You'll develop your forearm along the way and not spend as much time in the gym, too!

 

[diy-mark]

Copper to CPVC

If you are connecting to a metal system, such as copper, you need CPVC-to-metal transition fitting.

At the front of the house, where the water comes in, I'll have to cut the 3/4" copper pipe off. If I use CPVC, I had planned on connecting it at that point with a SharkBite. Will that work ok?

The issue is usually that if you screw metal into plastic you may break the plastic female fitting.

Yes, I've had that happen before.

You can screw a CPVC male adapter into a copper female adapter. Most fixtures will adapt to a 1/2" male threaded part to that is not a problem. You can get 1/2" ball valves for shutoffs, threaded or socket.

Yeah, I had to do some of this when I moved my pump from the house out to it's own 'pump house' out in the yard after we hooked up to city water.

If you are in an area subject to occasional freezing you can easily put in drains.

Not much freezing here and the two or three days we've had since we lived here have never hurt the pipes. Only rarely does it get down to 32 degrees.

I would probably go the PEX route if I could get a decent brand around here but it's looking like all I can find is Zurn and Nibco. Most places don't carry it at all. And having the convenience of a Home Depot around the corner is a big PLUS for the CPVC method. I'm not real good at being able to make a list of parts in advance so I aways end up having to go back and get more stuff.

Thanks for the link to the article. I'll check that out.

 

[diy-mark]

The tool isn't cheap (you can probably sell it afterwards, or maybe rent one), but Wirsbo is the easiest to install blind

Is that the system where the PEX pipe gets expanded and then placed on the fitting?

 

[Redwood]

Yes, Wirsbo is attached using the expansion method!

Wow! I just checked the price on the CPVC X MNPT Brass transition adapter
$8 ea.

 

[Bob NH]

At the front of the house, where the water comes in, I'll have to cut the 3/4" copper pipe off. If I use CPVC, I had planned on connecting it at that point with a SharkBite. Will that work ok?

That should work.
There is a 3/4 SharkBite x 3/4 FPT that would allow you to connect to the CPVC with a 3/4" male adapter.

I would be inclined to do that rather than let the shark bite the CPVC.

You might have to use a flexible copper connector at the hot water heater to adapt to the CPVC, especially if it is a gas water heater.
http://www.harvel.com/piping-cts-water-heater.asp

 

[B2CHR]

Been reading this post and though I would put in my 2 cents. You said you were cutting the 3/4 copper where it's comes through the wall. I would use pex and soulder on a 3/4 copper to 3/4 pex fitting on and go with pex. Seen cpvc fail to many times over the years. maybe it gets brittle over time, don't know. Where is your craw space door locater in conjunction to where your line comes through the wall? Needs to come through the wall, 3/4 over to the access door with a shut off ball value where you can reach it. You might need a PRV too if ones not at the meter. You will also need to have 18" of copper at the water heater. Can't pex down to it. Been using the pex at HD and so far so good. You can also buy bags of fitting at Lowes for around $10 to $15. Cheaper than one at a time at HD. Might be able to rent the crimpers (1/2 and 3/4) at HD or some other rental store for the day.
I use the 1/2 copper 90 pex elbows for all my fixtures. You can firmly attach them to the studs so they won't move when you go to turn off a supply value. Use a 1/2 compression value with these. Quick and simple. Just some thoughts.

 

[Jadnashua]

WIrsbo is the one that you expand, then slip over the fitting, hold momentarily until it collapses. Prior to expansion, you slide a reinforcing ring over the end, then expand both. Pex has a very good memory, and makes a good, tight connection. One disconcerting thing is that you can usually rotate the pipe on the fitting, but that's normal.

 

[diy-mark]

You might have to use a flexible copper connector at the hot water heater to adapt to the CPVC, especially if it is a gas water heater.

It's electric. And actually the copper on the water heater is fairly new so I just have to figure a way to tie into it with the new system because it's in a very tight spot.

 

[diy-mark]

Where is your craw space door locater in conjunction to where your line comes through the wall? Needs to come through the wall, 3/4 over to the access door with a shut off ball value where you can reach it.

My house is about 20 ft from the street. The meter is at the street with a shut off valve on the street side. From the meter, it comes through 3/4" copper up to another shut off valve on the outside of the house. So there are two places I can shut it off before it gets inside the house.

Then, 3/4" copper comes into the crawl space. Just inside the crawl space is where the 60 year old copper meets the newer 12 year old copper. That's where I have to cut it off because the problems are under the house.

You might need a PRV too if ones not at the meter.

It might be built into the meter, I don't know. But the pressure doesn't seem to be any higher than when we were on a well with a pump.

Been using the pex at HD and so far so good.

They don't sell it here in my locale (So. Fla.). I called them and they said they sold it 15 years ago but stopped.

You can also buy bags of fitting at Lowes for around $10 to $15.

But the Lowes here sells Zurn fittings and apparently people have had problems with that brand.

But maybe most people haven't had any issues with the stuff, who knows.

Thanks for the input.

 

[diy-mark]

Wirsbo/Uponor is the one that you expand, then slip over the fitting, hold momentarily until it collapses.

Yeah, and I see that the price of the tool will collapse your wallet too. YIKES!

 

[Redwood]

For hooking up the water heater you could put these on the water heater and flex it right over to your PEX or, CPVC.http://www.watts.com/pro/_productsFull_tree.asp?catId=64&parCat=326&pid=602&ref=2

 

[diy-mark]

Good idea, Redwood.