Upstairs Bathroom Addition

I am researching using a Saniflo macerator unit in a second floor bathroom addition. My house is on a slab foundation so there is no easy way to access a large drain line. I have a 2 inch Vent pipe which runs vertical through the outside wall of my first floor kitchen and then thru the attic and out the roof. The vent pipe has a cleanout plug on the outside of the house so I removed the plug and flowed water into the hole and confirmed it will drain. Since the discharge on the macerator is 3/4 inch could I discharge into the 2 inch vent pipe in the attic?

If there was a blockage, all that s*** would get pumped into your sinks, tubs, toilets, etc. downstairs. If you ran it down and joined the drain down on the first floor, say maybe from a sink, it might work. You'd still need to run a vent for the pump - you could joint into the vent line in the attic, but not with waste.

You would be turning the vent stack into a wet vent IRC says no wet venting between floors, if I understand you correctly, no for IRC/IPC.

Thanks for the advice. Could I discharge the Saniflo macerator into a washing machine drain. Can you put a "S" trap on the washing machine drain to keep the smell below that level.