[jasperjodo]

we want to turn the tub in opposite direction and replumb. fyi: changing all galvanized piping to copper for enitre house. will be using 3/4" soldered copper until vertical lines for fixtures, which will then be 1/2" soldered copper.

all fixtures basement and first floor only.

waste drain for tub in new position will be in way of "lengthening" old cold water supply following current plumbing route. won't be a problem for hot supply route.

any reason that we should not branch off (with 3/4" t) main (cold) supply line to tub before supply line reaches water heater? old house, so approx 30-35 ft to water heater as it still vents into chimney.

currently, hose bibb t's off supply line before water heater, which will not change. that branches off after proposed tub branch, but of course, before water heater.

cold supply after water heater would be to laundry tub and washer (basement); kitchen sink; toilet and bathroom sink (all main floor). tub just happens to be much closer to front of house like water supply line coming in, just on opposite wall.

Any input greatly appreciated!

Jasper

 

[Just Bill]

Not sure I understand your question. Branches are allowed anywhere in the line(hot or cold), it matters not where the heater is located. Hot and cold are seperate lines. Before the heater it is cold, after the heater ir is hot. And you are correct that all lines should be 3/4 as close to a fixture as possible.

Switching ends on the tub can be an issue for venting and drainage, but supply is not a problem.

 

[Mike Swearingen]

And your water pressure should substantially improve when you replace that old galvanized with the copper.
Mike

 

[TheEplumber]

If water pressure is around 60-80psi it is not uncommon to supply 2 fixtures on a 1/2" line. Unless you will be installing a T/S valve with multiple heads and body sprays, 1/2" will do just fine.