I am looking to put a basin into my toilet. The toilet is situated in the same room as the main waste pipe.
Next to the toilet is the bathroom which has a sink & bath. Both of these go into a single waste pipe which runs down through the floor and then along the ceiling below (boxed in). This runs directly under the toilet and where I am looking to put the basin.
Is it best to try and tap into the existing waste pipe going from the bathroom to waste stack for the new basin (will be very small so minimal use) or should I just run a new waste pipe and box it in along the bottom of the floor?