Sign In to join the community | Help
Build & Remodel

Breaking up concrete in basement to expose waste line

I need to completely replace waste lines in my basement.  It will save me a considerable amount of money if I can dig up and expose the lines myself.  We have exposed most of the line, the last 15 feet of piping (leading to the trap) is beneath concrete.  The pipe cannot be more than 5 inches at its deepest.  I have no idea how deep the concrete is.  What would be the best way to break up the concrete so we can dig out around the pipe.  Keep in mind, I do not want to damage the pipes, that would lead to a messy situation until the plumbers arrive.


If there are specific tools I need, please be specific, and hopefully it would be something I could rent for a reasonable price (trying to keep costs down). 


Thank you soo much in advance for your help.

Not what you were looking for ? Try posting a question
Posted 2012-12-21T19:19:11+0000  by DenaMarie DenaMarie

Hello DeneMarie,


Welcome to the community.


This is something that you can do yourself and the tools that you need can be rented at your local Home Depot Tool Rental center.


A typical cancrete slab is 3"- 4" thick. You can adjust the concrete cutter to the correct depth.


I had to do the same thing when I ran the electrical wires under my concrete patio to my garage. The previous owners to my house had layed a cancrete slab on top of another concrete slab. I had no idea until the saw was not going all the way through. I kept going deeper and deeper until I hit dirt. It was 7" of concrete. Not fun... Hopefully you don't run into anything like that.


I rented a concrete cutter to cut a channel into the concrete and then took it back and rented a jack hammer to break up the concrete into smaller pieces to get them out. Once you get all of the concrete out of the channel you will be able to dig the dirt out around the pipe.


**Make sure and wear protective eye and ear protection along with a pair of gloves.**


It will save you a lot of money if you do it yourself. My electrician was going to charge me $900 to do it. I’m not saying it was easy because it was a lot of back breaking work but we finished it in one long Saturday.


So if you’re willing to do some hard manual labor than take a trip down to your local rental center and pick up a concrete cutter to get started. They will show you the basics on how to operate it.


By doing it yourself you will save at least a few hundred dollars. :smileyvery-happy:


Let me know if you have any other questions. I would love to help.

Posted 2012-12-21T21:19:15+0000  by Christine_HD_OC

Thanks for the quick response.  I'm trying to envision what you described.  I think I get it, about using the saw to create a "channel" and then using a jackhammer to break the concrete into pieces that can be lifted and removed.  Not sure how to go about it so I don't damage the piping.  If I jackhammer the concrete directly over the pipe, I will damage the pipe, which will cause quite a nasty mess in my basement until the plumber can start work.  I'm not sure how to just expose the pipe without damaging it further.  


I was thinking of creating a channel on each side of the pipe, thereby allowing me to dig and expose the "sides" and bottom of the pipe but I'm still not sure how to handle the concrete on "top" of the pipe.


I appreciate any ideas.   Thanks again.

Posted 2012-12-22T18:04:19+0000  by DenaMarie

Hey DenaMarie,


Fellow expert 

Posted 2012-12-22T19:42:55+0000  by Joseph_HD_ATL

i noticed that they are recommending the use of both a saw and a jack hammer. if u must have a perfect line with trench then the saw is a must. if u dont u can use just a jack hammer. the pipes are normally far enough under the slab to break concrete without worry of hitting them. i would focus on finding how deep the shallow end is and work form there cause the line will get deeper heading downhill towards septic/ street.. hope this helps.

Posted 2012-12-23T00:34:45+0000  by plumberman

Hi DenaMarie


If you decide on using a concrete saw make sure that basement is well ventilated first. That’s a must.


These saws produce some serious emissions, especially when they're in full cutting mode... Many things are in the exhaust including carbon monoxide.


So please make sure that area is well well ventilated.


I normally set up things to where there's some cross ventilation and sometimes i even set up fans to pull the air in/out.


Plumberman made a good point, if you don’t care to have a perfect trench that you can break it all up with the jack hammer also.

I’ve done it both ways.


Sometimes saws are out of the question. Common example is doing a repair in a finished basement.


As far as the pipe goes, you never want to break the concrete directly above it. It’s not that pipe will break (it is possible) it is that you don’t want to “dive” your bit (jack hammer) in to the pipe. Your trench should be around 16”-20” in width… this said you would want to cut/break concrete 8”-10” from the center of the pipe. Pieces that are left floating in the center can be “worked” loose with the pry bar and picked up by hand.

I would leave section of the pipe where it exits the basement to the plumber. He’s probably going to tap in inside the basement.


Hope this helps,



Posted 2012-12-24T15:45:04+0000  by George_HD_CHI
Not what you were looking for ? Try posting a question