Hi,

I had my basement roughed in for a shower, toilet and sink. The pipe for the toilet sticks out of the concrete and is 12" from finished wall. There is a 2" PVC pipe behind the toilet that will be located within my framework. I am guessing this is the vent for the toilet and also a wet vent for the sink. There is another 2" PVC pipe coming out of the concrete to the left of toilet vent (looks like just the right distance away to be the shower vent). I am guessing that the P trap and drain for the shower is under the concrete floor located somewhere in front of this vent. I called the plumbing subcontractor that roughed the basement in 5 years ago. He claims that the tray and trap for the shower is located just under the concrete. He recommended that I tap around on the concrete and listen for a sound difference to know where to bust out the concrete. I tapped around with both a regular hammer and sledge hammer and could not hear any difference.

He also claims that I should have 3 vent pipes. He said that wet venting the lavatory is illegal. I did some reading on IPC and UPC codes and they claim that as long as the vent pipe is one size larger than the drain that wet venting is ok. So since the sink pipe is 1 1/2 inch and the vent is 2" I am guessing it is OK to wet vent the sink drain into the shower vent.

I guess my questions are:
#1. Is there an easy way to locate the shower drain (if there even is one) under the concrete without having to bust out a huge area of concrete?
#2 Is my guess for what all the pipes are and wet venting correct? 3 pipes total come out of the concrete. 1 for sure is the toilet hole located 12 away from finished wall. The other 2 pipes are 2" PVC pipes. One is located in the framed wall behind the toilet and the other is located in the frame wall (actually, only half the pipe will be in the framed wall... it sticks out slightly more than the other pipe. I need to bump out the framed wall slightly here or use 2x6) to the left of the other pipes.



Thanks!
Greg

Hi,

I had my basement roughed in for a shower, toilet and sink. The pipe for the toilet sticks out of the concrete and is 12" from finished wall. There is a 2" PVC pipe behind the toilet that will be located within my framework. I am guessing this is the vent for the toilet and also a wet vent for the sink. There is another 2" PVC pipe coming out of the concrete to the left of toilet vent (looks like just the right distance away to be the shower vent). I am guessing that the P trap and drain for the shower is under the concrete floor located somewhere in front of this vent. I called the plumbing subcontractor that roughed the basement in 5 years ago. He claims that the tray and trap for the shower is located just under the concrete. He recommended that I tap around on the concrete and listen for a sound difference to know where to bust out the concrete. I tapped around with both a regular hammer and sledge hammer and could not hear any difference.

He also claims that I should have 3 vent pipes. He said that wet venting the lavatory is illegal. I did some reading on IPC and UPC codes and they claim that as long as the vent pipe is one size larger than the drain that wet venting is ok. So since the sink pipe is 1 1/2 inch and the vent is 2" I am guessing it is ok to wet vent the sink drain into the shower vent.

I guess my questions are:
#1. Is there an easy way to locate the shower drain (if there even is one) under the concrete without having to bust out a huge area of concrete?
#2 Is my guess for what all the pipes are and wet venting correct? 3 pipes total come out of the concrete. 1 for sure is the toilet hole located 12 away from finished wall. The other 2 pipes are 2" PVC pipes. One is located in the framed wall behind the toilet and the other is located in the frame wall (actually, only half the pipe will be in the framed wall....it sticks out slightly more than the other pipe. I need to bump out the framed wall slightly here or use 2x6) to the left of the other pipes.



Thanks!
Greg

Hi Greg,

Where do you live that local codes call for 3 vents on a 3 fixture bathroom group?
Most bathroom groups are roughed in like this.
Toilet connects 4" to sewer main. The toilet wet vents through the lavatory vent. Lavatory connects to toilet drain and runs a vent out the roof off the top the stubout tee. The shower connects to the lavatory drain and is wet vented by it. This is a normal rough in and is acceptable both by local and state codes but also The Standard Plumbing Code Book.
If I had to guess at your set up as explained I would have to say that the pipe in the wall picks up the lavatory and vent. The pipe in the floor is the trap raiser to pick up the shower and you already know where the toilet goes.
I have worked all over the state of Florida and have never seen a shower raiser that was left buried under the cement. Good luck, Tom

Hi Tom,

Thanks for your input. I live in Naperville, IL and their website points to IRC 2000 for all building codes. IRC 2000 doesn't seem to dictate a vent for each fixture. I think the guy I talked to may have been new and pretended like he knew what he was talking about.

My neighbor had his basement bath roughed in for just a sink/toilet. There is the toilet hole and behind it in the finished wall is the vent for the toilet. These are the only 2 pipes. So the sink must drain to the toilet vent. This vent is 2" so per IRC code it should be ok for a wet vent.

I am banging my head on this hole shower thing. I read your response and don't quite understand it. My other neighbor had his basement roughed in for a full bath and he has a similar pipe situation to mine. His home was built a couple years before mine. This 2" PVC pipe for the shower sticks out of the concrete by a couple feet and it's location is such that 1/2 the diameter of the pipe is sticking out of the finished wall and the other 1/2 would be within the finished wall. I am assuming a 2x4 wall. If I make it a 2x6 wall, then both of the 2" pipes would be enclosed, but the toilet would be less than 12" to the finished wall. If this 2" pipe is supposed to be a vent for the shower, then it needs to be in the wall. If it is supposed to be a drain, then it needs to be brought out more from the wall. My neighbor with the similar pipe situation busted up his concrete floor by the pipes and did find this weird, flexible black plastic/rubber hose that is supposedly connected to a p trap and supposedly is the drain for the shower. According to my neighbor, they did it this way because they weren't sure where the drain location would be for the final shower fixture... that would make the 2nd PVC pipe a vent for the shower I guess.

I need to figure this out before I frame up the bathroom. I guess I could call a local plumber to come out and take a look and give me an estimate and then frame up the walls and then call him back out to do the work?

Thanks again for your time,
Greg

Hu Greg.
"If this 2" pipe is supposed to be a vent for the shower, then it needs to be in the wall. If it is supposed to be a drain, then it needs to be brought out more from the wall."
you're assuming that all shower drains must be centered. Not so! A custom tile shower drain can be anyplace as long as it has slope to it. My walk in shower has the drain located 4" to center off a 2X4 tile back wall.
Unless you had a inexperienced plumber do your home the 2" in the wall picks up the lav and vemts the system and the 2" out of the floor is the raiser that picks up the shower. Regards, Tom

Thanks Tom!

Greg

Hi Tom,

I busted up the concrete in front of shower 2" vent. Sure enough, under the concrete was a iron (or steel?) stub out that connected to the vent. The person who installed this roughed in plumbing had the stub out covered up with duct tape. I removed the duct tape to reveal the 2" diameter hole. There is no P trap. I will need to install this. I poured water down the 2" PVC vent pipe and no water came out the hole telling me that the pipe was sloped away from the hole toward the sewer. I then poured water down the 2" hole in the iron pipe and saw water flowing past the 2" PVC pipe (looking down the vent with a flashlight).

The shower fixture base I want to buy is 5' long and 33 1/2 inches wide they detail a special framing around it (10" centers). The hole for the drain is located in a very precise location.

The drain is located very close to where the P trap is going to be and it will be very difficult to line up. Do they sell a flexible P trap that is reliable enough to be placed under the concrete?

Thanks,
Greg

I don't know Greg,

This is not a typical rough in. You will have to break up cement and center the "P" trap directly under the drain in the shower base. I'll serch the net for a 2" flexible " flexible " trap but don't hold your breath. Good luck, Tom

Hi Tom,

Check this out: http://flexpvc.com/

They sell very durable, flexible 2" PVC pipe. They show a truck running over it and retaining shape. It is UPC approved and can be buried up to 2 feet under concrete. You can use standard PVC glue and cleaner on this.

Looks like this maybe a good solution to connect my P trap to shower floor drain. Will allow me a little wiggle room to allow for slight measurement error in the drain location.

What do you think?

I think youb diud a better job of seaching the web then I did. Go for it. Tom

Hi,

1st of wet venting a lav and a toilet is legal as long as you keep a 2" min wet vent between lav and toilet and keep a 2" vent min for both lav and toilet. Code call for 2" vent min for a toilet.
2nd, the extra pipe you see could be waste stack if your plumbing system is gravity drain thru the house. What that means is, the stack is provided for a fixture on the main floor.
3rd, It could be the drain for the lav only and didn't use it. Lav only requires a minimum 1.5" drain but generally subs run 2".
Basically the pipe behind the toilet is vent for it, and the other on far left is your shower drain. Thanks