Hello,

I searched the forums but couldnt real find an answer. Im installing a toilet in a new basement bathroom and am hoping to find another way of venting without busting up concrete. There is already a toilet flange installed in the concrete slab. It is only 12" away from the main drain line that goes out of the house. I am wondering if I could vent it by teeing off of the 3" drain that feeds the upstairs bath fixtures. Where I would tee off of this drain is only about 30" from the flange. Is this possible? There is nothing upstream from the toilet if this makes any difference. I've include a pic:



If this wont work, is there any other options for venting the toilet without busting up concrete?

Thanks for your help,

Todd