domgbrown

I was under the impression that all toilets needed a vent pipe. I am trying to tie a sink vent pipe into my toilet vent pipe, but cannot find the toilet vent pipe. I went under the house and found the drain pipe to the toilet. I pulled down some of the insulation, and it appeared that the drain connected directly to the bottom of the toilet because I believe I could see the bottom of the flange. The only problem is that the drain pipe connects directly to the horizontal main drain line and has no vertical vent. I drilled a 2" hole above the toilet to see if I was wrong and the drain pipe went up the wall behind the toilet, but there was no vent. I am sure that the drain pipe is under the toilet, because the toilet is directly across from the sink fixtures coming through the floor (I ripped out the vanity), and under the house the drain pipe is directly in the middle across from the fixtures going up through the floor. This house is in a subdivision built by Centex, and I'm sure it was built to code. All of the other faucets have AAV's on them, but I know that toilets have to have vents. Where is the toilet vent?!? I have attached pictures to give anyone who can help me an idea of what I'm talking about. The picture under the house shows the drain coming down through the floor and then going horizontal before going underground near the edge of the crawlspace. it does not connect to any vertical pipe that I can tell. How far can a toilet's wet vent go before it needs to connect to a vertical pipe? PLEASE HELP ME FIND THE TOILET VENT! Thank you very much for any help you may give me.

jerryh3

It's usually in the wall right behind the toilet. I don't think it can be any farther than 4' away from the toilet flange.

domgbrown

It's not though, I drilled a 2" hole above the toilet to see, and there isn't anything behind the toilet.

ranman469

it is probly wet vented. where a line picks up the toilet then tub/shower then turns up for the lav and continues as the vent.

domgbrown

That's what I figured, but the drain for the toilet goes through the floor and does not connect to any vertical pipe underneath. It goes horizontal for a while, and then goes into the ground. It is also a lot thicker than all of the other pipes underneath and the other pipes connect into it while it is going horizontal, which leads me to believe that it is the main pipe that connects to the sewer. If this pipe connects directly to the toilet and does not connect to a vertical pipe, how can the toilet have a vent?