I have include a picture of my roughed in basement. There are 2 x 2 inch drains and 1 x 4 inch drain. THe last one is the one I am vexed by. It is 1.5 inch and I assume I use it as a vent, but I am not sure what I need to do. Is it possible that all connections to the drains is under the floor and I just need to tie it into the main vent line?

The drains are all tied together bellow the slab. Shower pan is as indicated by red square. 1 1/2" line is shower vent + sink drain. 2" pipe is vent for toilet. Tied them together as indicated in drawing and continue upwards to the next floor and connect with existing 2" vent not lower than 48" above the floor.

That's only your drain rough in. You will be needing supply lines too. Milo gave you a good start so just come back when you want to do the rest of the piping. Measure from the center of that 4" pipe back to the stud to tell what size toilet you need, likely a 12".

Incredibly helpful, thanks. THe problem is that this is in the basement and I would have to tear out walls to attach upstairs. Can I not tie into the vent line somewhere in the basement? I followed a vent line that goes from under the slab roughly back and to the right of the picture and ends up going up the wall to the far left of this picture and joins up in the attic with the other vents.

Yes you can tie your vents together, they are not as temperamental as drains. Keep a well stuffed rag in that 4" pipe and pour some water down the 2" pipe before taping it shut with plastic wrap. Sewer gas is a bummer.

Thanks, I have the supply lines figured out, I am having trouble with the drains/vents. Another problem occurred to me from your diagram. There is not room between the toilet and shower to put a sink. I had planned on putting the sink to the right of the toilet, but now it appears I would have to "u" around the toilet vent to get to that drain. Am I wrong?

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Originally Posted by mulvax

Thanks, I have the supply lines figured out, I am having trouble with the drains/vents. Another problem occured to me from your diagram. There is not room between the toilet and shower to put a sink. I had planned on putting the sink to the right of the toilet, but now it appears I would have to "u" around the toilet vent to get to that drain. Am I wrong?

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You have plenty of space behind stud wall and drywalled(?) wall. For sink: install 1 1/2" sanitary T facing backwards, sideways, and to the right of the toilet. Insert 45 and extend the drain horizontally, and behind the toilet, to your new sink location. We call this "dirt arm". Otherwise, all your drain plumbing looks like it was done professionally.

Thanks. That is just a stack of drywall back there. It is actually a storage room I just wanted to keep everything in the wall if possible, but not a deal breaker. As far as the vent, where am I "allowed" to tie in to the main vent. I could go up and hook in between the floor joists or go the other way and hook in near where in goes in the floor.

You can connect still in the basement. You don't have to go all the way to the ceiling. Connect 48" above the basement floor and higher. If you run vent horizontally, maintain 1/4" per foot upward slope.

Cool. Thanks for all the help folks.

Something wrong here, Milo...

I'm thinking the 1.5" is for the shower vent...period. The 2" is a vent/waste for the sink and also acts as a wet vent for the toilet.

If the shower was wet vented by the 1.5" pipe it would need to be 2".

I think this should be piped up as drawn below... ;) Use a 2"x 1.5" sanitary tee to pick up the sink drain and then connect all vents as discussed above.

Let me know what you think all.


MARK

This was my initial though also. Good job Mark

Also, make sure that the pipe you connect vents to in basement isn't a drain for upstairs fixtures(toilet, bs, ks, etc). Needs to be a true vent with no waste entering it. Please let us know more about the vent you are going to tie into. Remember, even if it is a true vent, it will have to be at least two inch. Looks like a pro rough in as Milo stated. Just as well finish the job correctly. Only one other concern hear. It doesn't look like the toilet stub up was wrapped suffiently. Yes it is wrapped, but it should have been wrapped enough to allow space between concrete and pvc for closet flange install. Looks like you may have to do some hilti work to make flange fit on pipe. Just be careful not to crack the pvc. Or you will be breaking up more concrete than necessary. Good luck, please let us know how things work out. And enjoy your new bathroom.

Hi Lee:

Mulvax could also use a 4" TWIST and SET flange (see picture). Here, as you know Lee, he would need to cut the 4" PVC pipe flush with the finish floor and then grease the rubber seal and twist and push down to install the new flange. Then he would secure the flange to the floor using cement anchors/screws or similar cement screws.

In terms of venting, Mulvax should also be clear on fact that the vent fitting that he installs in the 2" vent in the ceiling needs to be turned backward... so water from rain can fall down pipes and flow, by gravity, down the vent to the drain pipes... hope that made sense?

Hope Mulvax returns... ;)

Have a good night all!

MARK

Makes sense. I agree about the twist and set for four inch pipe. But it kind of looks like three inch to me. Even though a three inch twist and set would work just fine, I don't like to reduce inside size of three inch.

Mark, I've never used a 3 inch twist and set.. one question(because I may use them in the near future) does the plastic cone on a wax ring fit correctly in one on these, or do you need to use a ring without cone, or cut cone off? When I think about it, using a wax ring with cone, would reduce inside size of pipe just as much as twist and set. HMMMM. Got me thinking now.

So I guess I'm saying, go with marks advice. He(once again) has the best sollution.

I also never use a 3" twist and set flange....restricts the drain too much...so I really don't know the answers here.

I do, however, think that is a 4" pipe... :p:p:p (But I've been wrong before! ).

:D

Hope Mulvax pops back to let us know... :rolleyes:

Goodnight!

I have installed several 3" twist-n-set and used a neopreme collar on the wax ring. It never came to mind that this could be an issue, so far no call backs so maybe it isn't an issue.

Thanks Ballengerb, I just haven't had one in my hands yet, so I didn't know if collar would fit. IF collar indeed fits, then I can't see any problem with them.

PS. Mark, the more I look at the pic, the more I also think it is four inch. Im just used to seeing pictures where the closest thing to the camera looks bigger than it actually is. Really wish asker would come back and let us know how things are going.