Back-To-Back Shower No Easy Fix | Showering Enthusiast

Journal Gazette:

Question: … I’ve changed many shower valves by going through the back of the wall, but now I have a shower valve job that has me a little perplexed. My job has a shower stall that is back-to-back to a tub and shower, and they both share the same wall with the plumbing lines and mixing valves. I’ve never seen a setup like this before. Have you? Will I have to open up one of the walls in the tub or shower? That would be a big mess. Or is there a way to install the new mixing valve from the front without destroying the tub or shower surround. To make things worse, they are both older tile jobs. What options do I have? – Dennis, Virginia

Answer: Sounds like this job is a menace! Unfortunately, I have seen setups like this before and whoever installs a setup like this needs to understand that eventually all plumbing fixtures will have to be serviced or changed. Many local codes do require an access panel be installed so there will be access to mixing valves. However, this might be an old installation, done before access codes existed.

Anyway, you do have two ways to do this and neither of them is going to be easy, so let your customer know up front this may be an expensive job. Hopefully, they won’t get mad at the messenger.

First, they do make extra-large stainless-steel cover plates for mixing valves sometimes called “goof” plates. These large flat, football-shaped cover plates may allow you to open a hole around the present mixing valve, remove the old valve from the front wall and install the new valve to the existing piping. After the valve is in place, the large metal plate should cover up the enlarged hole and allow the valve trim to be installed. But trust me on this – it’s a tight fit to change a mixing valve through a hole in a wall. And also risky if you need to solder joints with a torch in a tight area. Even though this type of cover plate may work, who’s to say that next year the tub valve next door won’t give you trouble because it’s the same age as the shower valve, and now you’re stuck again.

The second option, though, might give you more bang for the buck. Completely open the smaller tub front wall and re-pipe and replace both mixing valves. This will give you plenty of access to do the job and then you will have to match up the tile (as best you can) and install a new front tub wall to complete the job. I know it’s not a perfect solution to box everything in again, but at least it’s a fresh start. Sometimes you can only do the best with what you have to work with, and unfortunately because these fixtures were originally installed back to back, this job would have anyone up against a wall.