I've searched the forum a bit and haven't really found a solution. I want to put a toilet in the basement. The house was built in 1921 and doesn't have a roughed in point in the concrete floor for a toilet. I do want to put it directly underneath the upstairs bathroom. And all I want to do is a toilet and sink. Can I build the toilet on a platform in order for proper drainage to the main pipe? I assume it would be better for me to jack hammer the floor out and do it properly, but the funds just aren't there at the moment. And my skills as a jack hammer, well I don't have any. I realize how dumb this might be for someone using the toilet, but is it possible?

You have a vent problem going in, You could platform the toilet but what about the drainage from the sink and the vent? THe sink drain will have to connect to the toilet drain and either a vent run out the roof or a AAV installed. Your best bet would be to " bite the bullet" and take up the floor , cut a wye into the main to pick up the toilet and connect the sink drain downstream from the closet bend.
You will have to vent the sink either by running it out the roof or reventing back in the attic to a existing vent out the roof. Another option would be to install a AAV,(Air Admittance Valve) on the sink at its location. Good luck, Tom

Could you not have the sink drain towards the main pipe, and have another pipe run up to a higher location on the main pipe for venting? I believe that's my stack?

Could you not have the sink drain towards the main pipe, and have another pipe run up to a higher location on the main pipe for venting? I believe that's my stack?

If you connected the sink drain to your stack vent what would vent the toilet? Regards, Tom

You'll have to excuse my novice-ness. My upstairs bathroom, which I can see the drains from the basement, has the toilet drain running into the pipe that goes into the floor. The sink seems to do the same, but higher up. Same with the tub. And (my house is small) the kitchen sink has a drain pipe that travels all the way across my basement into the pipe too. And isn't the main waste pipe also the stack? Again, excuse my ignorance.