Consider a house whose tubs have old fixtures like this: old tub/shower knobs

I dislike them for many reasons, the main ones being:

  1. I prefer hot and cold not to be controlled separately
  2. I prefer handles instead of knobs
  3. I prefer not bending down to reach them [I shower 99%+ of the time (as opposed to using the tub), so I'm standing]

A solution where temperature is controlled via a handle that is separate from the handle that controls volume (like this) would be preferable.

modern shower handles

Obviously, I could hire a contractor to rip out the entire bathtub/shower and choose exactly whatever I want in its place, but that's quite expensive.

I'm wondering if there is a cost-effective way of achieving most of my goals without ripping out the existing structure.

Is there some "above the surface" type of solution that could "plug into" and combine the hot/cold pipes into one unit?

Even telling me the right words to use when searching for such a solution would be helpful. Thanks!

  • 1
    What is on the other side of that wall in the various tubs of interest? You'll need to get into it for most practical solutions.
    – Ecnerwal
    Jun 5, 2022 at 0:47
  • 1
    Sometimes if you are lucky, there is an access panel for the plumbing on the other side of the wall. There will be changes done to the pipes and the handles, you want to change from two to one. You can't get there from here, but usually not that big of a job.
    – crip659
    Jun 5, 2022 at 0:47
  • 2
    Looking at the picture again, that looks like a one piece tub and wall, which might make things more difficult, not much but holes will need patches/design features to look decent.
    – crip659
    Jun 5, 2022 at 1:19
  • 1
    Faucet hole cover seems to be a standard item that should cover the old holes. If the backside is drywall, you cut it open (and put an access cover there when done.) If it's tile you swear a lot and do the same thing with more effort.
    – Ecnerwal
    Jun 5, 2022 at 1:53
  • 1
    If you're in the US, before attempting a "simple surface mount bodge job", consider how expensive it will be to replace it with proper "behind-the-wall" plumbing before you sell the place. Very few other people will be willing to buy a house with a shower with exposed plumbing. Also, consider what that plumbing will look like - red & blue PEX? Soldered copper? Copper with SharkBite™ connectors? Any sort of surface mount plumbing will look like an amateur-hour hack job - future buyers will wonder what other short-cuts you've taken and will be very wary.
    – FreeMan
    Jun 6, 2022 at 13:30

1 Answer 1


What you are showing is just the front part.


You will need the actual valve, that looks like this.

Now the trouble starts. Guessing from your old stile you might have soldered copper lines.


This is how the valve looks like behind the wall.

valve back

In any case you will have to open the access from back (another room).

BUT they do exist: use the search therm

surface mounted thermostatic mixer

There are many surface mount models, so find the one that fits.

surface mount

  • Thank you! It sounds like from your answer and from earlier comments that there probably isn't a device available for sale that includes the valve in an "above the surface" way that I was hoping for (which would therefore not require cutting into the back wall).
    – Ryan
    Jun 5, 2022 at 12:30
  • @Ryan I did not say that. You could mount it above surface, BUT still have to connect it to the pipes.
    – Traveler
    Jun 5, 2022 at 19:04
  • Ok, I was thinking about the part where you said In any case you will have to open the access from back (another room). part. Good to hear that you don't think it's always necessary. Thanks.
    – Ryan
    Jun 5, 2022 at 19:47
  • @Ryan My answer was incomplete. BUT they do exist: use the search therm"" surface mounted thermostatic mixer
    – Traveler
    Jun 5, 2022 at 22:00

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