How to connect (wordy)

[billonion]

Help. I'm adding a 3/4 bathroom in my basement ( I have a 1994 2 story house with full unfinished basement). The toilet rough in is there, the drain for the sink is there, and the supply lines are overhead. There is only an opening in the concrete floor for the shower drain (think built-in kitty litter box). I dug down about a foot and found a 2 inch PVC pipe running through - see pic. I did a little testing and found this pipe to be the shower, sink and bathtub drain from the master bath on the second floor (water runs from right to left in pic). This is probably a simple question, but how do I attach and trap to this pipe? Do I come off the side and add a P trap or come off the top and install some sort of "S" trap? Of course, this assumes this pipe should be used for the shower drain......

Great site - Thanks in advance.

Billonion

[Terry]

If you add a p-trap to this line, you wil also need to run a vent for it.
The upstairs fixtures would siphon the trap dry otherwise.
If there is a vent coming from the slab for the shower, you might want to poke around a bit more and see if there is a 2" stub out for the p-trap.

[billonion]

There are 2 pipes (1.5 and 2 inch) to the left (not shown) coming up out of the slab. They run parallel to each other up about 4 feet, then the 1.5 inch turns and connects to the 2 inch. The 2 inch has the rough in for the sink teeing off it. Is this some sort of venting / wet venting?

Bill

[Terry]

If the tee for the lav is from the 2", that would be wet vented over the toilet.

The 1.5" line could be the vent for the shower.

I would be looking for a 2" stub for the shower, not the line you see in the picture if that is the upstairs plumbing.

[billonion]

If the tee for the lav is from the 2", that would be wet vented over the toilet.

The 2 inch must be the vent for the stool, as it is right behind the stool's rough-in. The tee for the lav is off this 2 inch.

The 1.5" line could be the vent for the shower.

The 1.5 inch line is over from the stool vent about 2 feet, fairly close to the pipe shown in the pic. I would assume this to be the shower vent, but this house has not been that agreeable. I usually have to undo 2 things in order to do 1 thing......

I dug down around the pipes in the pic some more and so far have found nothing.

billonion

[sulconst2]

sounds like its time to rent a jackhammer. since there is already a hole it will break out easy. plus nothing saying the existing hole will match up with your shower pan. bust it out. see what you have, then do it right. take pics as you go. good luck!