PEX Home Runs with Manifold

Are there alternatives out there?

Would I be hurting the value of my older home by installing PEX instead of copper? It seems clear to me that PEX offers several benefits. I no longer see that copper is superior unless I'm overlooking some key attributes.

I'd also like a way to measure water pressure. Would it be possible to put an air valve such that a tire pressure gauge could be used to read pressure?

How much pressure should I have at the the upstairs shower outlet?

Thanks for your advice.

ss370

You will not hurt the value if you use pex, pex is wildly used here where I live, it's about all we deal in, manabloc, we don't do, we plumb pex just like any normal house,

Test pressure with a pressure gage that connects to an outside hose bib, pressure on an upstairs could be as much as 5 psi lower then lower level, you lose 1/2psi per ft on the rise. So pressure will depend on what you have on the lower end.

IMO the manifold with homeruns is the better way to go. You don't need to worry about it being plastic, all water treatment (your softener/filter) is plastic and they don't fail. Going with the manifold, you can use smaller ID tubing than you would need with tee and elbow type plumbing.

Gary
Quality Water Associates

plastic

Saying, "all your water treatment is plastic and they don't fail" is over generalizing. I replaced a softener last week that failed, but did not flood the house. I am the process of litigation over a customer purchased softener that I "installed" eight years, and "failed" last year causing $25,000.00 damages. And from the numerous postings about them, we know that there are many others that "fail".

Yeah but... You need to use the implied definition that I am in this case of someone a bit uncomfy with using 'plastic' manifolds. And I'll bet any water treatment he has now or gets in the future is plastic and doesn't leak ever but... in regards to his post, what do you think he should do?

Gary
Quality Water Associates

IMO the use of a manifold seems like a lot of waste on piping, and I'd think it would cost more in material using the manifold system.

But it's your choice.

Good Luck on your project.

But PEX tubing is cheap compared to the labor to put in all the extra fittings and the cost of the fittings and the crimp rings to plumb PEX as copper or CPVC is. And the homerun way can use smaller ID tubing so it costs less than the larger ID teed and elbowed way. Add in the manifold and it's probably still much cheaper. And IMO it's a better system.

Gary
Quality Water Associates

Gary,

Would I get maximum pressure from 3/8" as opposed to 1/2"? The main reason I'm doing this project is to get decent pressure at the upstairs shower. I'm planning on running 1/2" unless I am be convinced otherwise. I'll run 3/8" for the toilets and possibly bath sinks and/or dishwasher.

Still unsure of the plastic manifold. I've seen it on that TV show and it looks very clean but I've never heard any first hand accounts. I'm sure it's fine. The only alternative I've seen is copper manifold with brass cutoffs. That seems less clean.

I'm glad to see that no one has replied that copper is necessarily superior. I'll bet that PEX rules plumbing within the next 10 years.

Thanks for the posts.

ss

Deb

I have had trouble with 2 of the plastic manablocks and I won't install another one, but I do like the home run system. I now just make my own, type L copper, tees, ball valves, pex adapters. The last one I did was in a laundry room. I used an in-the-wall medicine cabinet to mount it in--worked really neat.
The only thing I would run 3/8 to is sinks. I also install stops at all toilets. A quick turn of the stop (use the new 1/4 turn ball valves) can save a mess in case of an overflow. I run extra unused capped lengths to an accessible place (crawl space, attic) for future fixtures.
You need to determine if the problem to the upper shower is a pressure problem or a volume problem--different things. Are you putting in a new shower valve with the new water lines (recommend a new pressure balance valve). You should check both your pressure and your volume.
Deb
The Pipewench

The static pressure in a 3/8", 1/2", 3/4" or 1" is always the same. The flow (gpm) increases with each increase in ID. But you need to realize, all fixtures but a tub without a mixing valve are water conservation flow controlled to specific gpm ratings. So flow isn't all that critical as long as you have what the fixture can use at say a minimum of 30-40 psi. I've seen 3/8" homeruns in a number of homes and I've sold many softeners installed on PEX. I don't hear complaints, only how nice the water flow is. But you need to find what pressure you have or you may still have a problem upstairs.

If you were redoing the plumbing due to leaking copper, I would not use a copper manifold but then I would use the PEX type manifolds regardless.

Careful of dead ends, they are being outlawed in places around the country due to the water quality problems they cause. They can not (or won't) be sanitized and are a bad idea IMO.

Gary
Quality Water Associates

48 Psi

I have 48 PSI at the stand sink in the basement. After that there is a 36' horizontal run followed by a 16' vertical run to the shower. I'm not sure what my showerhead is but, assuming it is 2.5gpm, I want to be certain to get that maximum flow even if one or two other faucets are open elsewhere in the house.

That said, I think I'd do 1/2" PEX to the tub and 3/8" to the toilets and sinks.

Since I can't stand low pressure I was also thinking about a water pressure pump. It may not be totally necessary unless we have guests etc. Any thoughts on who makes a good pump?

Many thanks for all the helpfull suggestions.

ss