I am doing a bathroom in the basement of my house. I have to run 4 cold
and 3 hot (tub, sink, shower, and toilet). I am going to be coming from
3/8 ID, 1/2 O.D. Copper. I bought 1/2" PEX to run under the concrete
floor, I already have it broken up. I am using PEX because it's
seamless (zurn pex). From the copper lines off the water heater (hot)
and softener (cold) I am just going to cut out about 12 inches and add
reducers to bump it up to 1/2 I.D. 5/8 O.D. copper, because not only is
this the same size as the 1/2 PEX but also everything is cheaper in
this size, maybe because its standard. So I will cut into the 3/8
copper lines and add reducers to a 1/2 inch line with 4 tees in the
cold line and 3 in the hot. Off the tees, I will continue with 1/2"
down about 2ft from the ceiling (which is where the copper lines are
running off the softener and water heater) to a 1/2 ball valve,
continuing in copper again with a zurn pex copper to pex fitting at the
end. This is my first project with piping and it's quite a big one. I
fill fully confident I am able to do this just fine. My only problem is
every time I talk to someone about it, I am told a different way how to
do it. Even the guys at the hardware store have told me 3 different
ways to do it. The first time I had all threaded fittings with
compression for the copper. The second time, I had flare fittings with
threaded couplings, the third time, its now all solder fittings, no
threads except where the pex connects to the copper, that is some sort
of compression fitting, no choice I guess there. I feel this is the
best way, soldering everything, rather than compression, flaring, or
threading everything together, do you agree? Also, I am teeing into the
main 4" sewer line (stack) for all the drains. I have it dug up and
ready to cut. From what people have told me so far, I should come off
the 4" sewer line which is about a foot below the basement floor with a
4x4x4 Y and then have 4x4x2 tees off of that going to the various
drains, reducing to 1 1/2 when needed. And also reducing to a 3" for
the toilet. Or someone told me I could just reduce to 3 from right off
of the sewer (4x4x3 Y) and go to 1 1/2 right off the 3" line (3x3x1
1/2). Which is better, isn't bigger better? Thanks

wrote:
I am doing a bathroom in the basement of my house. I have to run 4 cold
and 3 hot (tub, sink, shower, and toilet). I am going to be coming from
3/8 ID, 1/2 O.D. Copper. I bought 1/2" PEX to run under the concrete
floor, I already have it broken up. I am using PEX because it's
seamless (zurn pex). From the copper lines off the water heater (hot)
and softener (cold) I am just going to cut out about 12 inches and add
reducers to bump it up to 1/2 I.D. 5/8 O.D. copper, because not only is
this the same size as the 1/2 PEX but also everything is cheaper in
this size, maybe because its standard. So I will cut into the 3/8
copper lines and add reducers to a 1/2 inch line with 4 tees in the
cold line and 3 in the hot. Off the tees, I will continue with 1/2"
down about 2ft from the ceiling (which is where the copper lines are
running off the softener and water heater) to a 1/2 ball valve,
continuing in copper again with a zurn pex copper to pex fitting at the
end. This is my first project with piping and it's quite a big one. I
fill fully confident I am able to do this just fine. My only problem is
every time I talk to someone about it, I am told a different way how to
do it. Even the guys at the hardware store have told me 3 different
ways to do it. The first time I had all threaded fittings with
compression for the copper. The second time, I had flare fittings with
threaded couplings, the third time, its now all solder fittings, no
threads except where the pex connects to the copper, that is some sort
of compression fitting, no choice I guess there. I feel this is the
best way, soldering everything, rather than compression, flaring, or
threading everything together, do you agree? Also, I am teeing into the
main 4" sewer line (stack) for all the drains. I have it dug up and
ready to cut. From what people have told me so far, I should come off
the 4" sewer line which is about a foot below the basement floor with a
4x4x4 Y and then have 4x4x2 tees off of that going to the various
drains, reducing to 1 1/2 when needed. And also reducing to a 3" for
the toilet. Or someone told me I could just reduce to 3 from right off
of the sewer (4x4x3 Y) and go to 1 1/2 right off the 3" line (3x3x1
1/2). Which is better, isn't bigger better? Thanks


Phew. How odd that the existing lines are 1/2" O.D. Most unusual.
Oh, well.

Sounds like all your soldered copper fittings will be above the floor.
Then PEX below the slab. Sounds OK.

On the drainage: I think you should be talking to your town/city
inspector; you may be headed for trouble.

My take on it: Use the 4X4X4 WYE to enter the existing house drain.
(4X4X3 WYE will work too, but that decision rests with the inspector.)

Use an appropriate-sized WYE (or long-turn TEE-WYE) for each
fixture branch; never use a SAN TEE in this kind of app.

Now, each fixture trap must be protected by some form of
venting arrangement. Here is where is gets sticky, especially
working under-slab. I would get a good book at the library or
BigBox on DIY plumbing and study it. Then talk to the
inspector to see what he will allow/require.

Jim

ABOUT the 1/2 O.D. everywhere, the water comes in at 1/2 I.D. then off
the water heater and off the softener it reduces to 3/8 I.D. lines
about 6" from the outs from there. Also why are you saying use long
turn tees? Just curious, whats the difference between that and a
regular y? For venting I just planned on using "quick" vents, they are
about $5 and allow airflow in but not out. Thanks!

wrote:

ABOUT the 1/2 O.D. everywhere, the water comes in at 1/2 I.D. then off
the water heater and off the softener it reduces to 3/8 I.D. lines
about 6" from the outs from there.

Ok, it's whatever it is.

Also why are you saying use long
turn tees? Just curious, whats the difference between that and a
regular y?

Long turn TEE WYE is useful because it gives you a
rt angle entrance with a gentle sweep. That or a
plain WYE will work if the layout fits.

For venting I just planned on using "quick" vents, they are
about $5 and allow airflow in but not out. Thanks!

Yah, they are handy, but I doubt that they would be accepted.
Maybe you're not subject to inspection, so that's your call.

1/4" slope per foot and you'll be fine:-)

Ok, no tees, just y's, I understand, I will stick with the 4x4x4 and
4x4x2 y's, if permitted, I will use long y's, Thanks for the tips! I
dont know if quick vents are permitted either, but it sure is strange
how the guys at the lowes can tell you to use this stuff then it not be
permitted by the city. Reminds me of the ventless gas fireplace I have
in my basement, I was told by my gas meter reader when he checked the
meter one time that I wasn't allowed to use it, against code or
something, but they still sell them at menards, lowes, etc... You can
buy em, just can't use em? I think if your not suppose to have them,
they should put restrictions on selling them in the area. I understand
the risk of a ventless fireplace but its made that way, and what can
you do about it. I never use longer than two hours at a time in the
winter.