On 03/09/2015 11:40 AM, Adam Kubias wrote:
On 2015-03-09 12:32 PM, dpb wrote:
On 03/09/2015 9:30 AM, trader_4 wrote:
On Monday, March 9, 2015 at 10:05:22 AM UTC-4, dpb wrote:
On 03/09/2015 2:53 AM, gregz wrote:
wrote:
I got a bathroom. I'm adding a second downstairs right below. ...
...
Run from hot water tank 20-25 feet, and cold tap. Still going to use
the
1/2 feed from regulator and hot water tank.
...

I think you'll be sorely dissatisfied by the result if there's any
possibility whatsoever the two are being used together. That line needs
to go to 3/4"...

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A big unstated factor is if the new bathroom is a full one, ie with
shower or tub, or just a half bath. Half bath, 1/2" would be fine.

I'd say "marginal"...

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Agreed. Usually the purpose for a second bathroom is if the first one is
in use. This negates that purpose.

Oh, it'll "work", just be annoying forever with slow-filling toilet, low
pressure/flow at the sink, etc., any time there's demand in the other
bath simultaneously. It's trivial to fix at the beginning but a
lifetime of aggravation thereafter if don't.

And for the "cheapskate" in the original post, the 1/2" there can be
salvaged and re-purposed for the runs in the new bath after the reducing
tee where it taps off the new main run. And, the 3/4" new run can be
plastic with transition to copper if _that_ concerned about cost.

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