Parallel supply lines

[Jarom Robinson]

Gentlemen,

I am installing plumbing for a walk in shower. Originally it was to be a delta valve and diverter, three body jets, a handheld shower, and shower head supplied by the existing 1/2” copper plumbing. Now changes have been made and I will now be installing a Moen Thermostatic valve, three volume controls, four body jets, a handheld shower, and a shower head, now needing a 3/4” supply. I believed that this would not be a problem as there was a tub that we were removing and a made the assumption that 3/4” pipe would be nearby before splitting to supply the tub and shower respectively. Now the demolition is done and subfloor has been removed revealing that the shower and tub remain separate and tie into 3/4” much further back under the finished master bedroom. So in conclusion, is there a code prohibition to merging these two sets of 1/2” copper lines into 3/4” to supply the shower? 2021 IPC, a reference would be greatly appreciated.

Thank you!

 

[Twowaxhack]

slab foundation or what ?

There’s no rule against connecting two 1/2” lines to 3/4 pipe.

I hope you have plenty of hot water supply, like a tankless or a couple 50 gal tanks

 

[Jarom Robinson]

No slab, I joists.

slab foundation or what ?

There’s no rule against connecting two 1/2” lines to 3/4 pipe.

I hope you have plenty of hot water supply, like a tankless or a couple 50 gal tanks

 

[Twowaxhack]

What’s below ? You can’t access the 3/4 from below ?

 

[Jarom Robinson]

What’s below ? You can’t access the 3/4 from below ?

Kitchen is below. I actually was able to remove a small section of subfloor inside the bathroom to get at this. When I first looked down the joist bay it appeared that the 3/4” pipes were under the master bedroom. After a second look I was able to determine that they were actually just barely inside the bathroom.