Re-locate Bathtub Supply Lines

[mk7474]

I'm in the process of re-modeling an upstairs bath, and need to relocate supply lines that lie under the sub-floor. The sub floor is tongue and groove pine (1.25" thick). From the pics you can see where the old supply lines came up through the floor (these fed a recessed jacuzzi tub that was removed). I would like to re-plumb to the faucet rough-in on the wall. My plan was to intercept the copper supply lines under the floor and adapt to pex before running up to the faucet supply. What is the best way to do this? I've sweated a few copper fittings before, but I'm not comfortable doing this between floor joist, where flame is a consideration. I was considering sharkbites or compression fittings but have heard mixed messages about both (in hidden locations).

Also, should the outlet box (shown in pic) be moved to accommodate the new supply line location? Thanks!

 

[frodo]

how big is the new tub? looks like the faucet you are showing is approx 30'' from the wall to center

most tubs are 30'', 32'', 36'' or 48''

reason i ask. if you are installing a lip or stand for the tub, run the water lines under the framing

i would use compression before i used shark bite

 

[mk7474]

Thanks frodo, the tub is one of those stand alone acrylic tubs. The unit will double as a shower. Tub is 59" long and 31" wide, and I plan on putting down tile as well. I'm located in upstate new york.

 

[KULTULZ]

Also, should the outlet box (shown in pic) be moved to accommodate the new supply line location?

If it was me, I would move the work box over so that any fixture leak would not get the box wet. It will be GFCI but why would you want to go back in there?

 

[frodo]

Thanks frodo, the tub is one of those stand alone acrylic tubs. The unit will double as a shower. Tub is 59" long and 31" wide, and I plan on putting down tile as well. I'm located in upstate new york.

confused, typically, if your tub is 31'' wide your valve is 15.5 center from wall.

confused as to the location of your valve, but hey,,your house, whatever you like

also, I see sheetrock on the wall in a wet area, that is BAD JUJU, the mold people will visit you
they are not nice guests. a bathroom is a "wet area" and gets greenboard

greenboard/purpleboard is moisture resistant
white sheet rock is not
or, use cement board. the best of all 3 for showers

 

[mk7474]

I understand. I should have mentioned that the faucet will be mounted over the side of the tub (not the end). I know.. unconventional The tub will have a shower curtain ring suspended from the ceiling and tile on the back wall. I am using concrete backer behind the tile. Since these walls are not 'wet', do you think greenboard is required on the 2 side walls? Thanks!

 

[frodo]

the whole shower enclosure is a wet wall, a bathroom is a wet wall because of the moisture/steam in the air

 

[frodo]

I am still confused. what is the hole in the floor for ? the one below the valve?

your idea to offset the valve, I like it.

you wanna get really freaky?

 

[mk7474]

Got it. One last thing.. For supply line compression fittings, I am transitioning from copper to pex under the floor. What would be a suitable connection?

1/2 x 1/2 mpt compression(copper side) -> 1/2 fpt pex adapter (pex side)

Teflon tape and/or pipe dope on threaded connection? Thanks again.

 

[mk7474]

Interesting idea there. Unfortunately the fixture I bought is an integrated unit with external mounted pipe for shower head and faucet! Faucet handle is connected to the tub spigot.

The hole below the faucet is where I am going to cut the supply lines and bring them up on either side of the faucet.