I am asking this question again - didn't get a answer last weekend.

I am considering adding a Basement half bath. I realize this is no minor undertaking. I have the venting designed, and luckily have a wall chase nearby to accommodate that. My question is about locating the existing sewer pipe under the basement floor so that I can tie into that. I know where the main stack clean-out is. There is another toilet stack from an existing 1st floor toilet across from where I would like to install the new toilet and sink in the basement. These stacks are cast iron, as such I would assume the pipes under the floor are also cast iron. Ideally, I would think that the sewer pipe would cross under the concrete floor nearby where I would tie into it. How can I be certain the pipe is where I think it is. Are there locators, or locating methods I could use? I don't want to cut into the floor and find out the sewer pipe is not where I thought it would be.

Appreciate your help.
Thanks,

Local Council should have plans of your building telling you location of sewage pipes. Unless you're in an old building.

Hope this helps,
Louis

Go rent a magnetic pipe locator.

Two year old post.

I saw that, but after 2 years none of the experts here could give an answer, or even understood the question...

And who's to say I won't be needing the answer! By the way, I do! So the magnet idea was helpful!