I'm planning on building a sauna with shower and a bathroom in my unfinished basement. I have no plumbing, but do have a 9' ceiling. Any advice or good links on plumbing under a subfloor? Thanks.
A 'subfloor' is the layer of (usually) plywood beneath your finished flooring. Are you referring to a concrete basement floor?
If so, you'll need to locate your existing drainline to determine what it will require to make the connection.
I didn't have any plumbing put in when the basement was poured, so I'll have to run plumbing underneath the raised bathroom correct? Won't I have to pump everything up to the existing drainlines? Plumbing would go between the concrete floor and the finished floor?
For a basement"
Option 1 - rip up concrete to install pipes
Option 2 - build another layer of floor over the concrete and the run the pipes under that - exactly like you would in any other situation.
Obviously, option 2 is a heck of a lot easier as long as you have the ceiling height to not miss 8" or so underfoot.
If the drain line is exiting your house above the lowest point in your new bathroom, yes, you will have to pump the waste up. At that point, it probably goes beyond a DIY job. Water and sh** roll downhill. You need to be 100% sure of what you are doing before you create an opening for them to roll down into your living space. This is not a lesson you want to learn by trial and error.