# manifolded water distribution, residential.



## jim connolly (Oct 29, 2010)

Getting into a bit more new-home construction this year, and mulling over the idea of setting up my waterlines in manifold format, with "home run" lines. For the guys who use this, what do you prefer? Is the Maniblock any good? Is it prone to any certain problems/issues? Or would it be better to just go with a job-built copper header with soldered-on valves?

When I worked for another employer, we just had a properly-sized main line with branches. I haven't turned my back on this approach yet either, but now that I'm working for myself, I'm looking at different ways of doing things.

Any thoughts??


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## plbgbiz (Aug 27, 2010)

If I were to do a "breaker box" set up I would do the job built you described. The Manibloc seems to be lacking in quality.


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## OldSchool (Jan 30, 2010)

Why would you want to run every line individually?

There is no beneift.....

material cost will be higher

labour cost will be higher

You will also use more water to get hot water at every fixture...

and it will look like hell

But hey if you want to do it that way .... go for it.... this is just my opinion


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## RealLivePlumber (Jun 22, 2008)

OldSchool said:


> Why would you want to run every line individually?
> 
> There is no beneift.....
> 
> ...


The manablock would use 3/8" tubing, and the delivery of hot water will be faster to each fixture. Other than that.............nada

Stick with conventional branch and tee layout.


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## greenscoutII (Aug 27, 2008)

Having installed a fair number of Maniblock systems in residential new construction, I have a couple of opinions on the subject.

For one, they seem to be a collossal waste of pipe compared to a home run system. 3/8 tubing was prohibited by local code where I was, so we had to run everything in 1/2. 

The maniblock is prone to leakage on the box itself and I really don't like the plastic shut offs. The whole thing just seems fragile to me.

I certainly wouldn't put one in my own house.


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## LEAD INGOT (Jul 15, 2009)

It's not a good system when you manifold. You take a re-circ out of the equation if the customer wants one. The long runs of 1/2" for outside hydrants leaves lower gpm from friction loss with out volume to back it up. With what you will spend in homeruns of pex, you're better off going conventional with copper. I'm sure some engineer with a background in electric, thought it would be a great idea to centralize water in a box, like an electric panel. But some things about this trade are best left unscrewed with. Especially if you are talking
about simple single family dwelling water distribution.


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## Plumbdog (Jan 27, 2009)

I have done a bunch of these in the past in both copper and pex, mostly in very high end custom homes of five or more baths. When using pex I use a copper manifold header. I don't care for the look of the maniblock. Too cheap. As not looking clean and neat that all depends on who's doing the install.

I'm not really sure if its something that you want to do on every house, but if you have a customer that is willing to pay for it then fine. People like to have the ability to go down to they're basement and easily indentify a fixture or group of fixture and shut them down if there's a problem. A manifold allows them to do that. 

As for re-circ lines thats not a problem. If the customer is willing to pay for the extra T&M to do a HR and mani then they won't blink at running the re-circ lines to it's own manifold.


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## 3KP (Jun 19, 2008)

here is a link to a maniblock system I installed 2 years ago. We do maniblocks in custom homes (per builder request)

http://www.plumbingzone.com/f21/pic-5500-sq-ft-house-i-did-652/

I like to run copper more I think it looks cleaner. But if you take your time you can make pex look some what decent!


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## Redwood (Sep 8, 2008)

Homerunning PEX is for guys that don't know how to size pipe and like to run spaghetti...:yes:

Take a look at this PEX Design Guide

In a smaller home I would run a trunk and branch system and in a larger home I would run a modified trunk and branch with remote manifolds which is shown below.


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## jim connolly (Oct 29, 2010)

Remote manifolds is not a bad idea....
The houses I have coming up are smaller, so there is not issue of a recirc line, based on this and other research the Maniblock is now out of the question. 
Might just end up going with the good old trunk and branch after all.


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## greenscoutII (Aug 27, 2008)

*Remote manifolds*

Yeah, I worked for a company in Colorado Springs (Fenton Plumbing) that did it this way. Works pretty well.


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## beavercreekhc (Mar 15, 2010)

I prefer the 3/4" Pex trunk line depending on fixture units for the water supply but i'm doing a new res. house right now with 4 1/2 baths and he wants everything coming off a manifold in the basement. I told him it was the worst idea he ever had. 2 story house with a hot tub on 2nd floor.. it will take forever to heat


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## t&kplumbing (Jan 15, 2011)

*manifold*

one of the bad things about a manifold system.. thats how i did the water lines in my house and the only thing i did not like about it is you have to wait for hot water to each fixture in one bathroom. now thats a waste of water..


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## SlickRick (Sep 3, 2009)

t&kplumbing said:


> one of the bad things about a manifold system.. thats how i did the water lines in my house and the only thing i did not like about it is you have to wait for hot water to each fixture in one bathroom. now thats a waste of water..


*Hello! Introduction Requested* 
An intro is requested from all new members. In case you missed it, here is the link. http://www.plumbingzone.com/f3/.

The PZ is for Plumbing Professionals ( those engaged in the plumbing profession)

Post an intro and tell our members where you are from, yrs in the trade, and your area(s) of expertise in the plumbing field.

This info helps members who are waiting to welcome you to the best plumbing site there is.

We look forward to your valuable input.


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## CAPLMBR (Oct 29, 2010)

Usually the way I run my system is to run 3/4" cold and 1/2" hot to bath locations and use flute manifolds set near center bath location (avoiding light cans of course). I do the same thing as I am branching down the system. Maniblocks suck imo. Things like kitchen, water heater, tub/shower valves and hose bibs all manifolded on-site in copper with transition fittings to the respective pex being used.


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## Skjay101 (Feb 28, 2011)

We run a 3/4" manifold with 1/2" outlets, in pex. With a very small amount of planning, and proper fastening, the home run pex system can be very clean looking (as apposed to looking like a spaghetti factory) and serves the major purpose of having no fittings inside the walls where they are often inaccessible. Each fixture also has it's own shut-off valve, which can be easily labeled in a mechanical room.


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## smoldrn (Oct 4, 2010)

I think a manifold would be good for maybe a vacation cabin, but when you factor in the extra piping, water usage & the fact that around here, the fixture is still required to have a shut off at the fixture, I don't see the point.


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## whitey (Mar 17, 2011)

The only way to do manifold plumbing properly is to use remote manifolds with a recirc line connected to each hot manifold. Otherwise you will have pissed off homeowners due to the fact that it takes literally minutes to get hot water flowing in their sinks/showers in the morning, or when ever a long period of time has passed since their last use. Most of todays fixtures are water savers, so they can only pass so much water through them at a time, now have a nice 100+ foot run to a master bath and watch how long it takes to get hot water there.

I worked for a large mechanical corp that does 95% new construction only, and for literally decades that was residential. Now they are into commercial but I worked there for several years and became very knowledgeable on some of this stuff. However, the higher ups in the company saw something about the manifold setups and fell in love on the spot, then decided to start having all our rough crews start doing this. It was ok in smaller homes with home runs, but I personally did the heating system in an 11,000+ sq foot house for one of our (better) builders personal home. I had to go back and split a zone of radiant into 2 separate manifolds and he started asking me why it takes so long to get hw out of his sink. I'm thinking a minute maybe, tops... well over 2 minutes.... do not put yourselves in this position. You will look stupid for offering such a complex system that does NOT work on top of the HUGE waist in material and time. 

The use of pex products were invented amongst other reasons to save us time and cut the material cost for water piping, not to increase job time and decrease the quality of the job, never mind how rediculas a big huge bundle of pex piping looks going through a 2x4. For cold water, ok....great, you have a shut off for each fixture. But really, how often is it the case that those valves will be used other than the homeowner playing with it, the less they can screw with the better. Every fixture still requires a valve at each, and its foolish not to install a ball valve on each separate riser, so in effect if you have that, you have done everything you need to do to make the job for the next person working on the home easy enough, if your smart enough to label what the valves kill, a better man you are. 

It will be less of a problem with 3/8 but non the less should be done with remote manifolds for each bathroom with a recirc, even if you maintain a low temp on the recirc it will be light years better than not having it. Also you will keep material costs decent and be able to offset the cost of the recirc a little. 

Seriously, I've been in some houses that were done by our company, and there would be a 1000 feet+ of pex piping where as if it was done with traditional style water it could have been done with 250-300 feet of mixed 1/2 and 3/4. Its insane whats being done today with the thought of being more economical or better, its really not. Think about it long and hard before waisting your time and money. This economy isnt the greatest place to be throwing money away.


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## VIPlumber (Mar 14, 2010)

******, how's about an intro?
http://www.plumbingzone.com/f3/.


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## whitey (Mar 17, 2011)

VIPlumber said:


> ******, how's about an intro?
> http://www.plumbingzone.com/f3/.


Sorry, didnt catch it but its been taken care of. All apologies.


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## CAPLMBR (Oct 29, 2010)

*Well said. A more descript version of my methodology.*

:thumbsup:



****** said:


> The only way to do manifold plumbing properly is to use remote manifolds with a recirc line connected to each hot manifold. Otherwise you will have pissed off homeowners due to the fact that it takes literally minutes to get hot water flowing in their sinks/showers in the morning, or when ever a long period of time has passed since their last use. Most of todays fixtures are water savers, so they can only pass so much water through them at a time, now have a nice 100+ foot run to a master bath and watch how long it takes to get hot water there.
> 
> I worked for a large mechanical corp that does 95% new construction only, and for literally decades that was residential. Now they are into commercial but I worked there for several years and became very knowledgeable on some of this stuff. However, the higher ups in the company saw something about the manifold setups and fell in love on the spot, then decided to start having all our rough crews start doing this. It was ok in smaller homes with home runs, but I personally did the heating system in an 11,000+ sq foot house for one of our (better) builders personal home. I had to go back and split a zone of radiant into 2 separate manifolds and he started asking me why it takes so long to get hw out of his sink. I'm thinking a minute maybe, tops... well over 2 minutes.... do not put yourselves in this position. You will look stupid for offering such a complex system that does NOT work on top of the HUGE waist in material and time.
> 
> ...


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## Walt (Mar 12, 2011)

*manifold confusion*

location, house size, recirculation, placement, convenience, water conservation, i am confused, cause these are the same questions i always have with on demand water heaters... are we designing plumbing systems for houses or houses for plumbing systems? ahhh so now we have the rest of the story(paul harvy):yes: the customer only knows what they think, it is our job to supply the facts of what we know based on experience..i have not even answered any questions just supplied new ones:whistling2:


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