Can I put a 32” x 60” curbless shower in a post tension slab?

I’m assuming this must be carefully chipped out, you can’t just send someone in with a partner saw.

2 Answers 2


The problem with a post-tension slab is that you, at this point, don't know where the tensioning bars/cables are nor do you know what parts of the slab are "structural".

Even if you can find the original documentation for the build, you will likely need to hire an engineer (i.e. one with a P.E. after his name) who is qualified with post-tensioned slabs and see if they can help you sort this out and give you safe solutions to your problem.

Otherwise, you may not be able to do what you want at all, at least not by cutting into the slab.

  • 1
    Even with original documentation, I’d still make a qualified individual say, “cut here” while they point to a spot. They should have enough insurance to fix a snafu. Jun 2, 2022 at 19:51
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    My point about original plans would be that it would allow an engineer to come to a conclusion more quickly. But I certainly agree, there is always the "as designed" vs. "as built" problem.
    – jwh20
    Jun 2, 2022 at 20:24

I did some research and this is what I learned.

You have to hire a person that does Ground Penetrating Radar(GPR) to identify the cables in the concrete and mark them on the floor. They will mark a square where you can cut into slab. If you decide to do it without this being done be extra careful to not nick the coating on the cable. If you do then it must be repaired or it will cost you a lot more when they have to repair it.

If you cut the cable with all that tension on it it can rip through the concrete which is not only an expensive repair but can severely injure or worse. From what I learned they're approximately 3-6 inches below.

I wouldn't hire just anyone or take someone at their word. I have heard of too many that mess a job up and disappear.

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