how do I know where to cute hole in basement floor to install rough plumbing for a toilet and a shower?
Is it better to use a concrete saw or a jack hammer?
Determine where you want your toilet and shower to be and hire a plumber to advise you about the waste run with slope to meet code. You will also have to cut a channel through the concrete to lay the waste pipe to where the plumber connects to the existing waste line.
When I broke the concrete in our carport's floor to run the waste pipe for an addition, I used a jack hammer. I figured that a concrete saw would need a diamond blade and create a ton of dust. If there are any rebars in the concrete, then additional problems using a saw.
Don't forget that you will need to install a vent pipe which the plumber can also advise you on how best to run it. It "may" need to be vented through the roof.