I'm doing a bathroom remodel in my basement. I have worked with plumbing before and fee confident when it comes to performing the actual work. A family member works with concrete removal/pouring so getting through the slab is covered as well. However, reading the code regarding DWV systems is overwhelming sometimes. I wonder if someone here could help me lay things out correctly?

This is what my bathroom currently looks like:

http://www.larryejohnson.com/photos/current.jpg

This was a half-bath. The previous owners replaced the vanity with a washer. As you can see, there is an adjacent room that isn't being used for anything. I would like the new layout to look something like this:

http://www.larryejohnson.com/photos/planned.jpg

Since I made that diagram, it looks like the utility sink will be to the right of the washer rather than where it is in the drawing.

The things that worry me most are making sure I use the correct size pipe given the number of fixtures and laying out the venting in a way that minimizes wall penetrations. Any help would be greatly appreciated, I want to make sure the job is done right.

I'll be more then happy to lay out your rough in but first I have to know the location of the sewer main that I'm connecting to and the direction of flow. It looks like the main stops at the toilet and flows to the right of the toilet, however I've learned not to assume anything in plumbing so if you would please feed me details, like, what material the present drainage is, how old is the house and will a permit be pulled on this job and a inspection called?
Am I looking at a tub or a long walk in shower? The name confused me. Tub or shower??
Regards, Tom

Thanks for the reply! At the moment, I'm working under the same assumption. I'll be removing some of the slab next week and at that time I'll know. When I get to that point, I'll post a detailed message with sizes, etc.

As for a permit/inspection I have no problems with that, but I'm told my county doesn't do inspections and I'm outside the city limits so they won't do an inspection either.

I would like to use one of the one piece shower units with tub if possible.

"I would like to use one of the one piece shower units with tub if possible."

Then I'm looking at a bathtub rough in. Correct? And let me know about the placement and direction of flow of the drainage as soon as you can. Please advise. Regards, Tom

Thanks for your help and patience, speedball. I still haven't gotten into the concrete because I was able to see the direction of the drain and also because I don't know exactly where to demo at this point. I don't want to tear up any more than I have to, I'm sure you know where I'm coming from there :)

I have a new layout...

http://www.larryejohnson.com/photos/brlayout.jpg

Here are a few particulars...

* As you suspected the toilet is indeed draining to the right at about a 45 degree angle.

* The center of the toilet flange is 19.5 inches from the right wall and 14 inches from the top wall in the drawing.

* The drain behind the vanity is a 2" drain and is 56 inches from the right wall.

* I have some flexibility in the placement of the washing machine and laundry sink left to right.

* We have settled on the shower unit shown here... 48" White 1-Piece Shower (http://www.lowes.com/lowes/lkn?action=productDetail&productId=102079-15728-314836BC00&lpage=none)

It is 48" long and 36" deep.

Now that I have removed the sheetrock from the top wall, I see that there is no vent... shouldn't the vanity have tied into the main vent?

I truly appreciate your help!

See how this works for you. The laundry tray will connect to the toilet drain and vent out the roof or revent back to the lavatory. The lavatory will connect to the L.T. drain line and vent out the roof and the shower will connect to the lavatory drain where it will be wet vented by it. I've tried to keep the fittings limited to common ones you can pick up anyplace. Did you want a floor drain anyplace? Regards, Tom

See how this works for ya. The laundry tray will connect to the toilet drain and vent out the roof or revent back to the lavatory. The lavatory will connect to the L.T. drain line and vent out the roof and the shower will connect to the lavatory drain where it will be wet vented by it. I've tried to keep the fittings limited to common ones you can pick up anyplace. Did you want a floor drain anyplace? Regards, Tom

Thanks for the reply. Am I correct in saying the shower is "wet vented" because it ties into the line from the lavatory which in turn is vented?

My only worries at this points are

a) I hope I have enough room to the right of the toilet drain to work without busting up any concrete under the wall or in the adjacent room.

b) Getting to the roof is going to be a royal pain. Assuming I can get to the attic, there is an existing 3" vent there. Is that large enough to accommodate tying this new 2" vent into it to avoid having another roof penetration?

Am I correct in saying the shower is "wet vented" because it ties into the line from the lavatory which in turn is vented?

Yes.

a) I hope I have enough room to the right of the toilet drain to work without busting up any concrete under the wall or in the adjacent room.
I've tried to hold the job to the confines of the bathroom, all that will go to the right of the toilet is a 4 X 2" wye.

b) Getting to the roof is going to be a royal pain. Assuming I can get to the attic, there is an existing 3" vent there. Is that large enough to accommodate tying this new 2" vent into it to avoid having another roof penetration?

You may revent back to a existing vent in the attic. It's also possible that local codes will allow you to install a AAV,(air admittance vent) in place of running a vent line up to the attic. Good luck. Tom

Got one more for you, then I'm off to bust up concrete.

Is it OK to use Copper supply lines under the slab? On the drainage side, would you recommend PVC or ABS?

We use copper under the slab all the time and in my area we switched from ABS to PVC 40 years ago. I recommend PVC for your drainage. Good luck, Tom

Ok, finally got into the concrete and found a few surprises that I'd like to run past you. First, the lav that was on the back wall doesn't tie into the line from the toilet at any point in the room. I suspect it meets up with it outside of the house. So my plan for the moment is only to add venting to that and use it as-is.

That leaves the washing machine and shower. I'm planning to use the same basic design you gave me, just a bit to one side now that I don't have to meet the lav drain any more.

The surprise is that after cutting off the toilet flange and looking down the pipe with a flashlight it is 3" as far as the eye can see. You mentioned a 4x2 wye in your earlier post so I guess you were assuming it was 4". So, my question is will 3" suffice for what I have planned here?

One other thing that my wife has requested is that, if possible, I install a laundry sink next to the washer. My initial thought was just to have the washer discharge into the sink. On giving it more thought, I think it would be cleaner just to tie it into the drain if possible. I'm curious about the pros and cons in your opinion. Reading online it sounds like discharging into the utility sink is a common practice, but I've never seen it done around here and think it might look a little unprofessional to future buyers who have probably never seen it done that way either.

Thanks!

You mentioned a 4x2 wye in your earlier post so I guess you were assuming it was 4". So, my question is will 3" suffice for what I have planned here?

Yes, 3 inch will work.

You're correct in assuming that discharging a washer into a laundry tray is both common and acceptable. Adding a washer stand pipe and another vent is overkill in my opinion. Regards and thanks for the support Tom