I would like to add a toilet in the basement of our 40-50 year old house but I do not want to rip up the floor. I know that I can use an upflush system like the saniflo but I would like to know if I could use a floor drain-its pretty much exactly where I want the toilet . I have 2 drains in the basement so if I could use one for a toilet I will still have one for is we have any flooding problems. I know that the floor drain connects to the same drain as the toilet upstairs because we had a clogged pipe on the city site and every time we flushed the toilet the drains would pump toilet water onto the floor - toilet paper and all- I also know that there is no grate or anything to stop largeer waster because when the town came out and fixed the clog they stuck a 2" wide snake 75 feet down the drain. The drain itself is 3 or 4 inches so it should be big enough. Im not sure if that would work because I'm not sure if there is a trap for the floor drain and I have read that you should not have 2 traps - drain +toilet. The other option I was considering is attaching to the main stack it is also within feet of where I would like the toilet and has a capped pipe that come off on an upward angle only a few inches off the floor, (clean ou I think )i would have to build a small platform for the toilet so it was above the pipe but if that is an option I wouldn't mind doing it that way. So is the floor drain or main stack an option? P.S I know the toilet must be vented.

Floor drain is a not go. Floor drains have traps, and your toilet already has an intregal trap in it, so your floor drain trap would constantly get plugged up. Cleanout may be an option if this isn't getting inspected, but still a no no by code. I say do it right and break up the floor. You will sleep better at night.