On Mon, 09 Mar 2015 18:10:34 -0400, wrote:

On Mon, 09 Mar 2015 13:16:21 -0500, dpb wrote:

On 03/09/2015 12:55 PM, trader_4 wrote:
On Monday, March 9, 2015 at 12:33:04 PM UTC-4, dpb wrote:
...

I'd say "marginal"...

I don't see why it's marginal. I have a 1/2 bath plumbed with 1/2" copper,
works perfectly. The tubing on the fixtures is down to just 3/8". What flow
rate do you think you need at a sink and toilet?

Bet it's not also on a main feed to a full bath _both_ of which are fed
only by 1/2".

If it's like my house it IS. 1/2 bath on main floor, full bath
upstairs AND the kitchen, all on one half inch line. Laundry too. 3/4
inch from the meter to the softener, 1/2 inch from the softener to the
water heater and to the cold water feeds.. Cold hard water to the
toilets and one tap in kitchen, cold soft water to kitchen and both
bath sinks, and tub. Cold hard water to outside hose bib.
Sum total of water supply lines in the house.


I have one bathroom. The feeders to tub and sink are 3/4".
About 5' runs.
The kitchen gets 1/2", about 4' runs.
The washer gets 1/2", about 6' runs.
The garden hose valves are both 1/2", short runs off 3/4".
It was done to Chicago code in 1960. Galvanized.
There are no problems except when one valve is opened the others slow.
That's normal to me.
Some of that is because the pipes are getting scaled up.
When I had a 2-flat with 2 full baths, 2 kitchens, 2 washers
everything was on 1/2" feeders. Chicago code circa 1928.
Galvanized.
No problems, except when one valve is open the others slow.
If that's not acceptable, go with 3/4". It'll slow less.