enter image description hereI have an interesting remodel project. I have an existing basement bathroom - which has a raised concrete floor. The toilet sits on the slab.

I am remodeling this to create a bigger bathroom for the basement, and the existing toilet and shower drain are very close together. I am thinking if I am going to do this right, I will have to break up all this concrete and then put them in appropriate spots.

Question: Is the toilet drain/water piping embedded in the raised concrete slab? Can I break up the raised floor without damaging the core stack and pipes?

  • 1
    I'm about to explore myself and would like to know what you found under your floor. Also, were you able to lower the plumbing in the ground.
    – Damisha
    Aug 27, 2018 at 3:32

3 Answers 3


Pull the toilet a look down the drain pipe. You should be able to determine what elevation the drain is running at, as well as what material the drain is made of. Both of theses will help provide you your answer. You'll need to buy a new wax seal for when you reinstall the toilet.


How much is the slab where the toilet sits raised up from the original basement floor level? Knowing this will help to understand if the add-on plumbing was placed on top of the existing floor or not.

If the plumbing was added that way then that was pretty much of a kludge scheme. The plumbing is usually placed below the slab in a bed of sand and then risers come up to the drain fittings through the concrete.

Without seeing some pictures of the installation it is hard to guess at how much infrastructure is built up around this raised slab area. My guess is that since you want to move the drain risers around that you may very well be best off to break out all the existing kludge of concrete and some of the existing sub slab to get the replacement plumbing put in correctly. There is very little chance that trying to save the existing plumbing is particularly valuable till you get down to where the original path went under the main floor. So I wouldn't worry too much till you get down into dirt.

  • 1
    Thanks. I will post a picture later today when I am back to the property. Its about 3 to 4 inches raised above the concrete floor. I need those 3 inches for head room. i only have 80 inches to work with as it is.
    – user23121
    Jun 16, 2014 at 17:59

Just a simple answer in case others have same question. You wouldn't worry about hurting plumbing when breaking up a basement floor. First the plumbing should have a little protection around it - usually rocks. Second it is just really easy to replace anything that breaks. I have broken up my share of basement floors and the only thing I have broke is old cast iron or clay piping and these things need to go anyway. So the answer is jackhammer/sledgehammer away. As long as you are semi paying attention your PVC will be fine and anything else should be replaced.

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