[PremiseDesign]

Hi,
I have a few questions regarding a basement bathroom. The house was just built, but there are no plans indicating the drain locations in the basement for the bathroom.
1. How high up do you have to build a subfloor for a basement bathroom when you would perfer not to have to break up the concrete? Or do you have to break up the concrete no matter what?
2. There are two pipes (I am assuming venting pipes around 2" diameter) plus the satck for the toilet that go floor to ceiling. Nothing else is there. Is the drain for the toilet underneath the concrete? Can you tap into the two other venting pipes and add the drains for the shower and the sink without having to break into the concrete?
3. How hard is it to move the drain for the toilet if it is in the wrong location under the concrete?
This is for a client of mine, and the way this basement is is stumping me. I have to draw up plans and I really want to make sure I understand what is going on.
Thank you so much!!

[Milo Dolezal]

1. You could get away with 2"x 8" floor. But 2"x10" and 2"x12" is prefarable
2. Post photo, please. But in the interim: the 2" pipes may by provision for shower drain and sink drain. Toilet should have 3" of 4" stub-out sticking up from the floor. The floor to ceiling pipe may be main sewer from floors above. You could possibly connect to it with new closet 90 fitting but you would have to raise your floor at least to 2" stub-out sticking up from the floor. The floor to ceiling pipe may be main sewer from floors above. You could possibly connect to it with new closet 90 fitting but you would have to raise your floor at least to 2"
3. Toilet is the "heart" of every plumbing system. It is lots of work to move it in concete slab.

[PremiseDesign]

Actually, I ended up figuring it out! Thanks for the info, too. It did help.
Thank you, thank you!

[speedball1]

Actually, I ended up figuring it out! Thanks for the info, too. It did help.
Thank you, thank you!

Did you get all your pipes identified? You've said you have it all figured out but allow me to answer anyhow.

1. How high up do you have to build a subfloor for a basement bathroom when you would perfer not to have to break up the concrete? Or do you have to break up the concrete no matter what?

If you're planing on cutting in a sanitary tee on the toilet stack then a 2 X 12 just ain't going to get it. When you figure in the height of a san tee plus the fall you're going to have on the branch line you better have a lotta head room in the basement. I would break up the floor and connect to the main.

2.Is the drain for the toilet underneath the concrete?(Yes, the sewer main is.. Can you tap into the two other venting pipes and add the drains for the shower and the sink without having to break into the concrete? No, You can't tie a basement fixture drain back to a pipe that has any fixture discharging intro it from above unless you revent that fixture back to a existing dry vent.

If you do not have a 4" toilet stub up roughed in you will have to connect to the main under the cement.

3. How hard is it to move the drain for the toilet if it is in the wrong location under the concrete?

I wasn't aware you had anything roughed in at all. If you don't see pipes ncoming out of da floor then I don't think you're roughed at all.Are there pipes already in place? Please explain.
If you wish to know how a basement bathroom group is roughed in most bathroom groups are roughed in like this.
Toilet connects to sewer main. Lavatory connects to toilet drain and runs a vent off the top the stubout tee out the roof or revents back into a dry vent in the attic.. The toilet wet vents through the lavatory vent and the tub/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 and also The Standard Plumbing Code Book in 90 percent of the country. Check your local codes to make sure you're not in the excluded 10 percent.. The vent off the lavatory may be run out the roof or revented back into a dry vent in the attic or if you're reventing back into a fixtures dry vent you must make your connection at least 6 inches over that fixtures flood rim. Good luck, tom

[PremiseDesign]

My client sent me a picture of it, and good thing as my memory was not serving me well when I wrote the first post.
So, they have the drain for the shower capped off as well as the toilet drain capped off, but with no flange. Plus, there is the main stack with a line coming off the side for the sink that is capped. It was really the layout that was odd and making my job of drafting up the plans challenging. I wanted to see how hard it would be to change the locations of things in case I could not make it function as they wanted it to. I did find a good solution in the end.Thanks for more clarification and info on plumbing. The more info the better as it is definitely not my expertise!Here is a picture nonetheless:

[speedball1]

That line going up better not be the main stack. It had better be the lavatory vent that vents the bathroom group. I was under the impression that you had to bust up the floor to install your group. Had no clue it was already roughed in. The plumber must have laid out the bathroom in his head before he did the rough. Can you contact him for more details? If you want to move anything in this rough in you're going to hafta learn how to wrestle a jackhammer. Good luck, tom

[Milo Dolezal]

It surely is a strange rough-in of your bathroom.. It's going to take some skill to design around it...

[speedball1]

Is that another capped off stub-up that I see over next to the water heater?
Regards, tom