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