Installing below grade Basement bathroom and kithenette must break concrete floor.

[Ethomas]

In a five year old new home I am finishing the 50x 38 basement. Rough-in plumbing for a bathroom toiet, tub, sink drain and ejection pump basin has been installed with pump 2" discharge and dry air vent pipes capped off in ceiling.

1: Toilet and tub drain locations do not fit my plan therefore I need the breakup the concrete floor and realign these drains. Will I encounter any environmental gases when I cut up the concrete.

2. I intend to do RADON short test while working the concrete. I will construct a 6 mill poly 4 wall and ceiling tent stappled and taped for concrete dust control. I layed out the outline of the main drain pipe going into the ejection basin. I marked a saw cutting grid along the location to the existing toilet drain. I intend to saw a 4" deep cross grid aligned with the pipe at the toiet drain. The cutting grid is based on 2" squares. With this grid cut I should be able to hit the center with a sledge and break out grid ( I hope).

3. I cannot use jack hammer (without emptying the china closet upstairs) What do you think of this concrete removal approach? I felt that with the concrete around the toilet removed it will allow me to locate the direction of the rest of the piping so I can repeat the cutting grid marking.

4. With sufficient concrete working area removed I can design the plumbing layout for my 34x60 multiple shower head (6) shower and 4" shower drain. Also to be installed is a dain from 48' perimeter wall pipe run to the kithenette prep/wetbar sink. This drain starts a 16" slopping 1/4" per foot to dump into the bath room behind the shower at 4"with 2 cleanout along the way each after it turns the corner.

5. The ejection pump discharge pipe passes through the basin cover 90 degree elbow to a diconnect coupling then a horizontal check valve (as stated by the pump) turns 90 degree upward to a gate valve and into the capped (removed) discharge pipe.

6. The pump vent pipe goes upward to the ceiling to join the now uncapped dry vent rough-in that goes to the roof. Can this vent pipe be joined with a 2 Tee's at the ceiling with the other vent pipes (vanity sink, utility sink, shower bathroom drain vent and wetbar sink) into the single dry vent to the roof????

[LonnythePlumber]

A sledgehammer is likely to cause as much impact on your structure as a jackhammer. You may want to consider cross cuts with your saw or are you planning on 2" cross cuts? That would be a lot of cutting and blade. Have you evaluated the difference in dry cut and wet cut? You can look in the toilet drain to see the direction it flows. You can tie the vents into the ejector vent.

[jdkimes]

From somebody that just recently cut the cement slab to move some pipes around:
Pay for a concrete cutting/coring company to do it.
I did some (very little) myself and some where I paid. It's worth the $100-$150 that you'll end up paying. And don't worry about cutting too much it's pretty easy to fill it in with cement when you're done but it's pretty hard to make the hole bigger. You could rent a wet saw but cost is not that much less than paying someone to do it.
The plastic tent around the cut will keep the dust down a little but the person doing the cutting will not be able to breathe.
If you do a radon test and have to put in sub-slab mitigation you can have them cut/core the hole for that too(unless you have a sump- in which case you won't need that radon hole). I just put in a radon system myself too.

Anyway that's my two cents if you're still thinking about it. Curious how it worked if you already did it.

[daveydo]

I just finished a similiar project. I opened a concrete floor and installed plumbing for 4 fixtures. My first approach was as you described. I had thought that a saw would make a nice clean cut and that's what I wanted. On second thought, that's not the type of cut I needed. A rough edge is much better as the new concrete (patch) will adhere to this type of edge much better.

Anyway, I was ten minutes in when I abondoned the saw. The dust was unmanageable. A water spray created a stream of mud and I had trouble managing the water spray to the blade. Even with hearing protection the noise level was high.

I then rented an electric jackhammer. It worked fine. Dust was not an issue.
Now I need to qualify this by saying that I had much experience in my younger years with pneumatic jackhammers. So, I was suspicious at the probable effectiveness of an electric. Again, it worked fine.

You need to know that this is no smalll task. The floor can be in the area of 3.5 " thick. The jackhammer is a very heavy tool. You need to be fit. Also, hearing and breathing equipment is recommended.

If you are inexperienced with a hammer you can crack up the floor pretty bad. It is a job that requires a great deal of labour. You also need to consider disposal of the removed concrete.

Finally, make sure there are no buried lines in the floor,as it was a practice in some areas to do so.

[Terry]

I contract to a concrete cutting company.

He brings out a "wet saw" with a diamond blade and a heavy duty "wet vac".

He runs the saw, I keep up with him on the wet vac.
He has both the gas wet saw for big jobs and an electric one for when the big gas cutter doesn't fit. In addtion to that, he brings out a 60 pound jackhammer, heavy sledge hammers and digging bars.
Cutting with a wet say means no dust and the job stays clean.
Existing concrete stays in better shape, and pouring new concrete is easier with the straight edge.
You can always rotohammer in some pins or bars to keep the new concrete patch in even with the old.