How to Attach a Tub Drain to a Shower on a Concrete Slab

I’d like to remove my bathtub and replace it with a walk-in shower, but my home is on a concrete slab, and I’m worried it will be too expensive to tear up the concrete to move the drain. What should I do? -Lee

Hi Lee,

You have a couple of options when using the existing bathtub drain for a new shower on a concrete slab.

Option #1: Custom Shower Pan

One way to go about it would be to have a cultured marble shower pan custom made to fit the location of the existing tub drain. Many contractors who do this type of work may already have templates for a shower pan with the drain on one end.

Chances are, however, that your drain may not perfectly line up, and a custom pan will have to be created. It’s more expensive, but it removes any worry of having to trench out the concrete slab.

Option #2: Move Existing Drain

The second option is to buy a standard 60” wide shower pan with a center drain, and cut a trench through the concrete slab from the tub drain to it. Believe it or not, it’s not that hard to cut a trench in concrete slab if you have the right tools. I did this very project in my own home several years ago, and it took less than 15 minutes to break up the concrete using a jack hammer from a tool rental store.

You don’t have to tear up the entire bathroom slab, just create a 12” wide trench from the existing drain to the center of the shower area. Once done, it’s a simple matter to replumb the drain, then mix up some cement and fill the trench. You now have a slab with the drain in the right location for a new shower pan!

Good luck with your project,


Further Information


  1. Love your show! Have 2 questions:
    1. I want to replace a noisy fan/vent in my bathroom. I DO NOT have attic access. How hard will this be?
    2. My shower diverters (in both bathrooms) are not working properly. Too much water going into tub vs shower. Hard water is most likely the cause. Any easy fixes?

  2. I have a shower in the basement bathroom. I would like to replace it with a bathtub. I heard for tubs the concrete needs to be cut up. is there any way to avoid cutting the concrete such as raising the tub up enough to get the proper drain pipes above the cement level except for the original drain that was used for the shower.

  3. I have the opposite situation plus one more concern. We have a 60 inch walk in shower in our main bathroom with a center drain. We want to put in a tub shower combination but can not find a center drain bathtub. The next obstacle is that the bathroom a is on a concrete slab within floor hearing so we are afraid to cut into the concrete not knowing where the heating coils are.

    What would you suggest?


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