Raising bath/shower valve - sweat or sharkbite

[loehrm]

Hi all,

I am installing a soaker tub. Since it is higher than the old tub, i need to move the spout and diverter up higher.

I've attached a picture of the current plumbing setup. I plan to cut the copper just below the diverter elbows and use PEX for the new connections.

I know i could connect to the old copper using sharkbite fittings and then transition to PEX. I think the right thing to do would be to sweat on PEX adapeters.

My worry is that I won't be able to drain the water out of the risers enough to properly sweat the adapeters on.

Any advice on what the right course of action is?

Thanks!
Ruel

 

[Jadnashua]

Since none of the valves will work properly with PEX to the tub spout, you'll have to deal with soldering. Given the small amount of copper needed, the fact that PEX has a smaller ID and therefore could limit the flow rate when trying to fill that new soaker tub, I think it's probably not a very good idea to use PEX in this situation. You could probably reuse the riser to the shower head after cutting it off, but otherwise, PEX could be used for a single shower head without issue. You should also be seriously considering replacing the valve, as depending on how old it is, it may no longer meet current code, and an inspector would require it anyway.

 

[Sponsor]

 

[loehrm]

Yes, I will be replacing the valve and will absolutely use copper for the spout. The question really is whats the best way to connect the hot and cold lines to the new valve. I'm afraid I won't be able to drain enough water out to sweat fittings on. Is there any tricks for that?

 

[Jadnashua]

To drain, shut the house water supply off, then open the lowest tap in the house. YOu need to do that for both the hot and cold. Many houses in TX are built on a slab, but it's easier if you have a basement. A wetvac can help to get enough water out of the supply lines to solder properly. Note on many valves, you can either use the valve body as a fitting and the pipe will fit in and can be soldered, or you can solder on a threaded fitting, and then use pipe dope or tape (or both!). Soldering is better and cheaper.

 

[Dj2]

I would do all new connections in copper only.

To get rid of rising water in the pipes, there are other ideas that I've used successfully.
- "the white bread" idea: insert some soft part of white bread into the pipes, which will absorb the water. Quickly do your connections. Before you install the valve, flush the bread out.
- Use a hand pump to suck the water out. A dry towel is good too.
- Use your torch to "cook and steam" the excess water.
Remember, all you need is to suppress the water a few inches. The pipe has to be 100% dry where you solder. Then quickly to do your soldering. Experienced plumbers do it routinely.

 

[Terry]

I pull the cartridge from the valve while soldering. I reinstall the cartridge afterwards.
Sometimes, if the water heater is siphoning, I will loosen the supply lines to it to break the siphon.

 

[Plumber69]

Maybe it's just me but that copper looks in bad shape. The 3/4

 

[Dj2]

Maybe it's just me but that copper looks in bad shape. The 3/4

From the two couplings down to the concrete, the copper is soft, usually used in slabs. The green on the copper tubes doesn't mean they"re no good.