Adding bathroom in basement, existing first floor bathroom waste stack 3" comes down the wall and then 90 through the wall at 7" off the basement floor into the septic tank.
Toilet will be 4 ' from this pipe.
see attched photo.
Because of the main stack exiting through the wall I will need to have the bathroom floor built up, I'm trying to keep the height of the floor at a minimum.
Do I need to add venting to the toilet?