Hi,

I have an older house, 1961, there's a toilet, sink and a deep sink all connected to the same drain line. All 3 are located in the basement. All drains and waste lines are in the concrete floor so there's no access to them other than a jack hammer and that's not an option.

The toilet will not flush properly. The water does go down but takes approx. 35-45 seconds to drain so it's not functional to actually "use".

The lavatory sink is right next to the toilet and I added and AAV to the drain line of the sink below the trap on the sink. I thought it would fix it but it didn't. You can hear the AAV open and close when the sink is draining but not the toilet. However the sink and the deep sink (about 5 feet away) drain exceptionally fast now. Normal I suppose but compared to before it's fast. I know the drains for the sink and the toilet are connected because when I plunge the toilet water comes up the sink drain.

Is there any way to "vent" the toilet without destroying the floor or calling a professional plumber?

I've read you can raise the toilet off the floor 10-12" and add another AAV/studor vent/cheater underneath the toilet using a "sanitary T" but I really don't want the toilet that high off the floor. I'd have to build a deck under it or something. It would truely be a "Thrown"

I pulled the toilet off the drain and set it on 2x4"s, filled it with water and flushed it. It works as it should. I also "snaked the drain pipe and there's nothing in the 4" drain pipe. As soon as I put the toilet back on, new wax seal and all it won't work again.....

Anyways I'm stumped...

Thanks in advance