I am renovating a very old house that I live in. Plumbing is in the
CRAWL space under the house, a very small tight crawl space. Drain
lines were broken when I moved in and new leaks and breaks every
couple months or so. House was built in the 40's, plumbing and
electrical look way older than that if you ask me. Most of the drain
lines are lead and the P traps are old school, look kinda like large
coffee cans. Since I'm under the house already replacing drain lines,
I would like to go ahead and replace supply lines. I know the house
has a .75" or ¾" PEX supply line from the meter to where the break was
just inside the crawl space. At that point it connects back to the
origional steel suppley line. The supply line has branch lines running
to the cold water faucets (toilets, showers, and washer) before ending
up at the water heater. Same for the hot water side leaving the water
heater. It branches off to the needed hot water faucets.
My question is if this is the best way to run the lines when I replace
then. I've seen instalations where they use a manifold type
connection with multiple ports that feed everything from that central
location. Or is the branching off the supply line a better way. Or is
there an even better way of doing this that I might not be aware of?
A home run system is cool, but it can require running a lot more
tubing and also requires a manifold which aren't exactly given away
for free at plumbing supply stores. I've never heard that they are
better except you can turn off fixtures at will from the manifold.
Since you have a crawl space, you'd also need some sort of mechanical
room to locate the thing. IMO you are better off with a traditional
Well I am relocating the water heater, furnace, washer, and dryer to a
utility room which could also be a location for a manifold. But if
thats the only pro to having one, I think I'll go traditional. Also
I'm just trying to avoid problems like getting all cold water in the
shower if someone uses the kitchen sink or flushes a toilet. I'm
guessin the manifold would also use alot more pex tubing since all
runs would have to be a home run to the manifold.
go with manifold no joints, you can make a manifold by using pex
better flow, easier service, pex is cheap, no Ts in inconvenient
temp shower valve is well worth the expense and still a good idea even
with individual lines
What do you mean by no joints? All of the pex I see going into new
houses has as many 90 degree ells as copper did, practically. You
really can't crank the stuff around a corner..you have to put a 90 on
it. I'm also wondering why you say better flow? Do you know this
From what I've seen, they don't use 90 degree fittings, they use plastic
clips that hold the PEX in a 90 degree sweep, and this would indeed give
less flow resistance than a "hard" 90. Perhaps the ones you've seen are
installations by "old school" plumbers who haven't quite adapted to the
No I work for a builder, so I see a lot of plumber's work. We have
three different plumbing contractors that we use. They are not old
school. I see 30 year old plumbers putting them in on every house I
work on. I haven't seen someone using bend supports once, except when
something is going to get buried in concrete.
I thought the whole point of using PEX was to eliminate as many connections
as possible, particularly ones inside of walls where the mechanical seals
could leak unnoticed for some time. This would rule out Tees and Ells and
promote home runs from a manifold and using curved tubes to make 90 degrees.
I certainly though that was supposed to be one of the big advantages,
coupled with the flexibility that allows you to fish it continuously.
Exact same idea as the flexible stainless gas line that's beginning to
replace the old black pipe with all it's potential leak points.
My current home
(1930 1 1/2 story; two ~stacked baths, laundry room & kitchen)
was re-plumbed with a home run system (valved manifolds).
I looked at it both ways & to me the home run system seemed best.
Yeah, it used more tubing but way fewer connections & no fittings
except at the fixtures & the manifold.
The stuff is pretty flexible (not like a garden hose but way more
flexible than soft copper) easy to snake thru walls, ceilings & thru
I like the home run method; continuous runs from manifold to fixtures,
not connections to make or leak along the way.
For a larger or spread out home, a traditional branch & main might
make more sense.
a hybrid system with some branch circuits & extra remote manifolds.
The home run system makes instant hot water loops harder to implement
but if the layout is compact & the tubes are sized right the wait for
hot water will be short even without a hot water loop.
The longest wait I have for hot water is ~ 30 secs & I waste less than
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