I'm planning on moving my toilet from one side of my bathroom to the other. I plan to tap into an existing drain for a bathroom sink (the sink will be moved elsewhere). I'm not sure about the compatibility of the drain pipe diameters, so I guess that's the first question. If they are not compatible (i.e. 1 1/2 for sink drain vs 3" for toilet - I have no idea), then I assume that I'll need to find the "main drain" pipe and work from that point out to where the toilet will eventually reside. It is in a slab. Call me crazy, but I'm not all that adverse to going into the slab to do what I need to do. I think I'm mainly just looking for an answer to sink drain pipe diameter vs toilet drain pipe diameter.

Art H.