water pipe dimensions?

[LouRocco]

Hi All,

I’m installing some fixtures in a multifamily house (4 apartments). Most of the water pipe is already there, but I have some concerns about the dimensions. Currently, the water pipe after the meter is 1†copper which branches into two 1†cold lines (one serving east side apartments and one serving west side apartments). The 1†lines also branch to four ¾†lines that feed 4 separate water heaters. Pipes out of the water heaters are also ¾â€. All pipes then reduce to ½†before going up to the various fixture clusters. Are the ½†“risers†up to the fixtures sufficient, or should I up some of them to ¾â€? Currently, there are ten such “risersâ€, one for each of the ten rooms listed below.

APARTMENT DETAILS
East A – all fixtures on 1st floor – Kitchen: kitchen sink
Full bath: toilet (old -- >5 gal/flush); lavatory; tub/shower combo

East B – all fixtures on 2nd floor – Kitchen: kitchen sink
Full bath: toilet (new – 1.6 gal/flush); lavatory; tub/shower combo;
Laundry room: clothes washer

West A – all fixtures on 1st floor – Kitchen: kitchen sink
Full bath: toilet (new); lavatory; shower

West B – 2nd floor fixtures – Kitchen: kitchen sink
Half-bath/laundry: toilet (new); lavatory; clothes washer
3rd floor fixtures – Full-bath: toilet (new); lavatory; tub/shower combo

Any suggestions would be greatly appreciated.

Thanks,
Lou

 

[Redwood]

Typically the water line would be 3/4" with 1/2" going to each fixture then when it gete to the last 2 fixtures it tees into 2 - 1/2" lines.