On Oct 20, 8:56 am, "Ivan Vegvary" wrote:
I want to redo the piping to one bathroom plus a garden hose bib. My
neighbor has a Wirsbo tool with both 1/2" and 3/4" expanders. BTW, this is
code legal and standard practice in my County. Job is under-house with
generous workspace.

Question:

I know what to do if I were using copper. With PEX do I simply run supply
lines (hot and cold) to the vicinity of the fixtures and then change over to
copper for the risers? Do I buy a manifold and split the PEX near the
bathroom and run individual PEX lines to the fixtures? BTW, the bathroom is
being gutted and I will have access to all of the walls.
It would be nice to have no copper under the house due to freezing, although
no pipes have frozen in the last 20± years.

Please advise as to common practice.

Thanks you very much,

Ivan Vegvary

That's a whole lot of questions...unfortunately the answer.....it
depends.

Depends on the house / bathroom (& kitchen / laundry) layout.

The layout for a 1 1/2 story house with stacked bathrooms would be
(should be) different than a spread out ranch style.

The house I just did was a 1 1/2 story house with stacked bathrooms.
I put the manifolds in the tiny utility basement with the water heater
& did home runs to every fixture.

Maximum wait time for hot water (kitchen & laundry) is 15 seconds.
Upstairs bathroom wait time is less than 10 seconds.

A spread out floor plan might benefit from a remote manifold (if there
are mulitple bathrooms far from the water service & water heater). A
hot water circulating systems might also be a good idea.

I had a different house but sold it before the re-pipe. The galv pipe
was so badly choked & the runs so long that the hot water wait time
was 120 seconds! I had planned remote manifolds to service to back
to back bathrooms. Total demand was 7 colds & 5 hots...so manifolds
make sense.


My bias is towards an easily accesible manifold with home runs, only
connections at manifold & fixture shut off.

As to copper risers, PEX can easily make the sweep bend up through the
wall plates. Metal & PVC sweep supports exist. I prefer to use all
plastic PVC electrical conduit to protect the PEX (no kinking on bend
& acts as a sleeve through the plate)

I got my stuff from pexsupply.com they have all sorts of fittings,
even PEX drop ear elbow for threaded stubs or PEX "bullet" stye
terminations.

PEX may be more freeze tolerant but its not "freeze-proof"

cheers
Bob