View Full Version : Crzy Rough-in Dim's HELP SEE PIC

Fairway Fatty
11-07-2004, 07:04 AM
Hello, I am in the planniing stage of finishing my basement. It is a poured foundation with concrete slab floor. I am stumped on how to do the bathoom with the floor roughin the contractor left me with. Any help is appreiated. See the dim's in the pic. Thanks. FF

11-07-2004, 10:17 AM
What you are identifying as the shower drain is probably the vent. Pour water in this pipe. If it runs away then there is no trap and it is a vent. If water stays in the bottom of the pipe it is the trap for a shower. Shower drains must be accurate and bases and their drain outlets are not uniform. Therefore we do not install the traps until the fixtures are set.
I think your wall line is that of the shower and toilet vents. You should have 12 1/2" from the center of your toilet flange to the studs. That means your vent will be at the very edge of the plate. You may have to install a 45 immediately to get your pipe back in the wall. The shower/tub drain is probably below the floor in a one foot sand box. Sometimes you have to hit the floor with a hammer to find it. It's probably right in front of the shower vent (if I'm right) or out five feet if they were planning a tub.

11-07-2004, 10:48 AM
I think that Lonny has given you a good assessment of what you have (I always label pipes coming out of the concrete in case I don't do the finish).
A shower or tub p-trap needs to be located exactly right, so tubs and showers are normally boxed out at the approx p-trap location and a capped horizontal pipe (the trap arm) is left in the ground to connect the p-trap to. If this was meant for a shower, use a hammer to tap the concrete about halfway between the pipe and the wall for a boxed out place that got covered with a skim of concrete. If a tub, the box out will be near the pipe.
The Pipewench

Fairway Fatty
11-07-2004, 05:42 PM
Thanks for the replies. I appreciate the advice and hope to "coerce" a bit more as I'd like to continue my CAD layout but this bathroom still has me stumped. I have a few more questions if ayone can can help.

I cannot find any trace of a "sandbox" for a tub/shower drain.

Would the rough in piping in the slab typically be done by the plumber who did the entire house? (I may be able to contact him to ask his intent)

You commented that the probable wall "line" would be along the shower and toilet vent pipe....if those are both vent lines.....where would the sink drain?

Other comment was 12 1/2" clearance is needed for toilet... I have 12 1/4"
you suggested 45 deg. to get back in to the wall. Some manufacturers have toilet for 10" clearance...... any reason why ths would not work?

Is the pipe that is 12 1/4" from the toilet flange specifically to be used as a vent line?

Does this athroom have to be vented and if so how/where do I tie it in to vent outside.

Thanks again. FF

11-07-2004, 06:03 PM
To me, it looks like a toilet and a lav.
The lav being near the wall.
You don't mention pipe sizing, but I'm guessing the 2" is near the toilet flange.
Is the other pipe 1.5" or 2"?
Lavs can drain with a 1.5" pipe.
Shower drains are 2".
That would be the inside pipe dimension.

I don't think you have a shower rough-in.
If you want one, you can cut the concrete and replumb the rough-in to include it.
The vent will need to either go to the roof, or use something like a Studor Vent.
If you look up, you may see a capped off vent coming down that you can connect to.

Most toilets rough in a 12" from the finished wall, with some models working at 11.25"
I wouldn't go to all that work of finishing and leave it at a 10" rough.

Here is a picture of how other plumbing is done.


11-07-2004, 06:41 PM
This is a rough in typical in my area where the lavatory wastes into the toilet vent. My inspectors would not approve the underground without a tub box. I don't know where fatty is or his area's practices but speaking from my area this is a normal layout. I have to break out concrete at least 1/3 of the time to relocate drains so this one is better than many homeowners get.
10" toilets are expensive and the first goal is to locate the edge of the stud wall 12 1/2" from the center of the toilet flange. That means the vent pipe should be 14" from the center of the flange and needs to move back 2 3/4". It would be better to break concrete but you can install a 45 right at the floor and kick back into the wall. This will leave about an 1 1/2" out of the wall at the floor for about 1 1/2" high. You can also replace the current flange with an offset and move the toilet out into the room instead of trying to move the vent back. Some consider offset flanges problematic but others have not had problems with them. How this wall will line up with the other vent is also a consideration.
There should be a capped vent pipe up in the joists. If not and your washing machine is hooked up the plan may be to hook into it's vent. I wish Terry would not use the term Studor but this is his site. To locate your tub box you could check with your neighbors if they have had their basement bath finished or you could check with the plumber than did your rough in. Your inspection department will know who this is from the permits. You could also ask them if it's possible for you not to have a tub box.

11-08-2004, 04:42 AM
The problem is that you do not know the exact purpose of each of those pipes, so we cannot either. And the pipe's purpose would tell us what the plumber had in mind when he put them in. There are many ways that the pipes could have been installed if they were just providing for a sink and toilet, your configuration being just one of them. But your configuration could also be for a three piece bathroom if there is a branch line, with or without a trap, under the floor. You might be able to determine that by looking down the pipe to see if there is an opening to the side of it under the floor. The toilet flange is closer to the vent, and therefore to the wall, than a normal installation, which will limit the toilets you can use, and also require a more expensive toilet unless you move it.

11-08-2004, 08:05 AM
If you believe that you can get ahold of the original plumber, that it your best bet. Under normal circumstances, one plumber does all the plumbing.
The Pipewench

Fairway Fatty
11-13-2004, 04:15 AM
Thanks for all of the replies....... great insight. I am out of town on field work assignment so at this point i am unable to do the "pour" check or visually take a look down the pipes or for that matter see if there is any evidence of a "sandbox"........ but i will as soon as i get home. Everyones posts have been great help. I have been away for 2 months and have been trying to layout my floorplan in my after hours but as i stated earlier the bath stopped me in my tracks. I hope to be able to get around this without a lot of slab cutting but sounds like mght be inevitable. I live in Virginia and unsure of code but will call inspectors office and hopefully get more info when I get home. (Hopefully in 10 days). Thanks again for the help. FF