[miamicuse]

Looks very nice and neat.

A couple of questions as I am in the planning stages of doing something similar.

(1) Any reason you decide to build your own 3/4" manifold on the cold side? Is it cost? Is it not being able to find one with the exact number of ports you need?

(2) Similar question on the 1/2", you are using manifolds but opted to put your own ball valves on each outlet port instead of those manifolds with integrated valves, is it because of cost? or you like the full port ball valves because they are more serviceable? or other reasons? Additionally, on the 1/2" valves since they are so close together to each other, can you turn one on and off without the handle running into the adjacent fitting?

(3) You are using the ProPex system. How do you like them? I am curious about the actual joints. Once you expanded the tubing and collar, and put them into the fitting, when it's ready (I heard it takes 20 minutes before you can pressurize), is the joint fixed in place, or can it be "swivel" some? In other words, once a joint is completed, can the metal fitting turn or rotate about each other?

(4) You mentioned no intermediate joints between the manifold outlets and their respective fixtures. So that means quite a bit of tubing. So you are running say 4 dedicated tubing to the kitchen area - one cold for icemaker, one cold for faucet, one hot for dishwasher, one hot for faucet, correct? Similarly, you will have one dedicated hot to run to the shower, and another dedicated hot to run to the faucet. Two hot lines to the bathroom means you have to wait for hot water both at the faucet and at the shower/tub. I am struggling a bit with this tradeoff to the farther bathrooms myself. Two lines vs one line and a tee on the hot side.

(5) Another one I am still debating is the hose bibb at the shutoff. Typically the main coming from the meter will enter the house and there will be a shutoff valve there, as well as a hose bibb because it's convenient to put one there. To have a dedicated line for each fixture including hose bibbs means the bibb right at the shutoff need to be redone. Instead of a branch off the main before entering the house it needs to be connecting to an outlet off the manifold which means in my case that water has to run to my garage and back, a 100 feet round trip. I am leaning to leaving the hose bibb there and save the extra 50 feet of tubing.

I am also thinking of PEX-A because of it's more flexible tubing and no need to work a crimper on a joint that may be in tight spaces.

 

[miamicuse]

Sorry to be confusing. If you missed it, look in the body of your quoted comment in my last reply. I amended it with my responses.

Thank you for the response. Very informative.

As far as question #5, what I meant, and may be this is a regional thing, but down here we almost always have a hose bibb where the main supply enters the house, and the shutoff is typically right after the shutoff and before it enters the building. Here is an internet picture of what I am talking about:

Since this hose bibb is one of the fixtures in the house, when redoing everything with home runs to each and every fixtures, it means this hose bibb has to be removed and moved, since it has to be controlled by a dedicated manifold valve. In other words, instead of being inline or just branched off the main, this hose bibb will need to be moved a few inches away, supplied by water running through the main to the manifold and back. I have seen it done both ways, just debating whether it's worth the additional tubing.

 

[miamicuse]

I understand now. I’m assuming that hose bib is for draining the system as it appears to be at a particularly low point? If you cut the main and opened your fixtures along with this hose bib, it’s seems like it would be pretty effective. Regardless, I would say negate it entirely in your new build unless you actually use that bib. In my case, I will have 4 hose bibs and one 3/4” for future expansion. Each of those 3/4” valves has a vent cap on the downstream side of the valve. If needed for an unlikely freeze here in NC, I can shut the hose bib cutoff valves, open the vent cap, and open the actual hose bibs, draining them.

It is not for draining the system, where we are in south florida we do not have freezing issues so no need to drain the system except in repairs. We have high water tables so no basements, so most times the supply piping runs below grade under the slab and pop up in another room like the kitchen or bathrooms. So a bibb at 12" or so off the ground cannot drain the system. We put it there because it's convenient to have a bibb there.

When repiping the new tubing typically will go through attics and run down.

Just to confirm, if you need to turn the manifold ball valves on and off for the 1/2" that are so close together, you will just deflect enough to operate the handle. Another option is to rotate all the valves say 45 or 90 degrees so your handles can turn out from the wall.

I am also tempted to build my own manifold valves simply because I do not see many PEX A manifolds available. When they are available they are not the same number of ports I need. So for example if I need four 3/4" ports and six 1/2" ports I cannot find one that does that. If I do find one it's twelve 1/2" ports. If I do find a ten 3/4" port manifold with valves I need to transition the 3/4" valves to connect to 1/2" piping so it means no matter what I do I have to customized it myself to some degree.

 

[miamicuse]

It would seem rotating the valves to operate them would be problematic once the pipes are connected. If I was doing it like that, I would remove all the handles and create a handle (or modify one of those) so that you put it on the one you need to close when you need to close it, and you can operate any of the valves without moving pipes around, or swiveling the connections.

The manifolds with integrated valves have those tiny little knobs/handles so there is no interference. The down side is they are not serviceable and I am unsure when one of them fail say in 3 years do you have to replace the whole thing by taking everything apart or whether you can replace a failed valve easily.

Building your own valves allows more customization such as being able to get a 12 port 3/4" manifold and use five 3/4" valves and five 1/2" valves and still have two left over for future expansion. The down side is extra work to make your own and deal with the handle interference. I suppose you can rotate each valve 90 degrees (handle will point towards you and away from the wall when closed) and just leave them all in that position, Or to get valves with "butterfly" style valves.

 

[miamicuse]

Agreed. In case I wasn't clear, I wasn't suggesting replacing the valves. My suggestion was just to remove the handles from all the 1/2" valves and keep one handle handy to slip back on one valve at a time to operate them as needed.

That would work but then the issue with that is there is no visual indication if a valve is on or off when you stand back and look at the entire system. If you are in the middle of trouble shooting a leak going back and forth to the fixture and turning this on and that off, you will pull your hair not be able to see what's going on quickly and easily.

 

[miamicuse]

Maybe not from across the room, but from a few feet away, you can tell which valves are on or off without the handle.

Yes but it would drive me nuts to have to look closely at each nut stop to verify "everything else is off except the upstair shower hot side"

 

[miamicuse]

I hope that was a joke. Running separate lines to each fixture is a common, probably the most common, way to configure a PEX system, since the pipe is relatively cheap in comparison to the fittings. It has some significant advantages in pressure balancing, and also, as you mentioned, being able to quickly and easily isolate each fixture.

Yes, home run PEX is fairly common and typically done with no intermediate joint which is kind of the point of using PEX. I have seen videos where the joints bust apart under high pressure. I have also seen videos where the pipe itself burst and the joint didn't. Heck the current 2021 class action lawsuit against Uponor for the colored red and blue tubings is for joint issues. It claimed that when the pipe ends are expanded to make joints, the red and blue pipes had micro-fractures due to the red and blue coating flame adhesive process. This and the company continued to sell the red/blue saying it wasn't discontinued before they came out with the white tubing with red/blue lettering to replace them.

‘Discontinued’ Red, Blue Uponor Pex Piping Plagued by Cracking Defect, Class Action Alleges

A class action alleges blue- and red-colored cross-linked polyethylene tubing (PEX) made by Uponor is defective and prone to premature degradation, deterioration and failure.

www.classaction.org

I bought the new white tubing with red/blue lettering. I understand the old white tubing was ok too, just the red/blue tubings. OK may want to look into this if his is Uponor.

As far as doing home runs for each fixture, the only practical downside I see is in bathrooms and kitchens on the hot side supply. Let's say your bathroom is 40' away from the water heater. So you have a 40' run to the shower hot, and a different 40' run to the sink faucet hot side, assuming you do not have a recirculating system, when you turn the sink on and want hot water, you have to wait for the hot water to come through the 40' of pipe. Then you jump into the shower, and you have to wait for that hot water again. If you run one single hot, and split off to the shower and sink, you do not have the second wait. Same situation with kitchen faucet hot side and dishwasher hot. Now if they are close by then it's a non issue. In my case I have a close by kitchen and a far away bathroom, I did the individual run to the kitchen on the hot side but a single run to the bathroom for hot only then split off.

 

[miamicuse]

That's assuming you typically need hot water for both one right after the other. That would be rare in my bathroom. On the other side of that, a line serving 2 or more fixtures would usually need to be larger (or you'll have pressure drops if they're on at the same time). Larger pipe means a larger volume of water sitting in the line, assuming ambient temperature. That means running the faucet longer (and more water wasted down the drain) at either one to get hot (or cold) water. Bumping up from 1/2" to 5/8" (assuming you can find 5/8") increases that cross-sectional area by 45%, which increases the time to get hot water to the fixture by that same percentage. To go up to 3/4" from 1/2", the increase is 97%. I'm not seeing any advantage to the shared line there, but some disadvantages, at least for the way we use water at my house.

Obviously it depends on usages and usage patterns, and what's rare for you may not be rare for me.

I often turn hot on in the bath sink to shave, then jump into the shower right after. Or I may rinse off the plates with hot water in the sink, then put the half rinsed plates into the dishwasher then run the DW. To me that's a fairly typical use case.

On the other side, do you still run a 3/4" to so you can split that into two 1/2" to serve two fixtures? To prevent simultaneously usage? I would say this is rare IF that someone does not use one fixture requiring hot supply right after another fixture also requiring hot in the same room. In the old days the typical use case would be when someone is taking a shower and someone else flushes the toilet causing the cold supply to lose pressure and the shower suddenly turn scorchingly hot. This was a problem on the cold side only, and no longer an issue with all the pressure balance valves and anti scald temperature limiting devices.

Since I am in south Florida, we don't insulate our pipes. To me running individual lines to each fixture in the same "room" on the hot side is something I am still on the fence about. Last time I had to decide which way to go, it comes down to how much tubing I have left in the 100' coil LOL.

 

[miamicuse]

Huh? Why would branching a 3/4" line prevent simultaneous usage? Serving 2 fixtures with a 1/2" line wouldn't prevent using both; there just might be a noticeable, even undesirable, pressure drop with both open.

A poor choice of word on my part. I didn't mean prevent simultaneous usage, I meant to allow simultaneous usage with a 3/4" line branching into two 1/2" lines without loss of pressure like flushing a toilet and burning someone taking a shower, which is no longer an issue today because most faucets and shower have anti scald features and pressure balancing valves, and we are talking about the hot side supply anyway.

I did it both ways (individual hots and separate hots for the same room) and there are pros and cons. I have ran a single 1/2" hot line to one bathroom for both sink and shower/tub. No issue. If you look at most shower valves and the channels inside, even though they may be a 3/4" port valve, the inside channels are often less than 3/8". Then most showers have the flow retrictors now. Same with a lot of the faucets. The only thing inside the bathroom that really use close to full flow is the tub spout, and I don't remember the last time I took a bath. Even in that case, on the way to the tub spout, it goes through a valve with tiny channels anyway.

The other fixtures I struggled with deciding running all individual lines to are hose bibbs. If you have one on each exterior wall, do you run individual lines to them all? That's a lot of additional lines and valves, and hoses can truly use 3/4" especially if you have 3/4" full port bibbs to do stuff like filling up a swimming pool it could make a huge difference in how long it takes. You could easily burn 200 feet of 3/4" on hose bibb lines.

Last time I did a PEX repipe, I had all 100' coils, of 3/4" and 1/2". I was pretty proud that I end up with 8' of 3/4" and 5' of 1/2". Virtually no waste!