[jameslrice]

Hello. I've spent hours reading through old posts on basement bathroom rough-ins, and I'm definitely more enlighted now than I ever was. But... I have no experience with plumbing and am not confident that I understand all the information I have found on this board well enough to be sure what I want to do is possible. Any additional help would be greatly appreciated!

Sorry for the long description but I figure it's better to be as detailed as possible.

I have an 1941 house with a crudely finished basement. The previous owner laid out a few walls decades ago using cinder blocks but they are poorly placed and ugly. I plan to remove these and completely finish the basement including a bathroom and laundry room. I will do much of the work myself, but I will bring in a professional for the plumbing... but I'd like to know the feasibility of my plan before I get too far, as this will greatly affect the design.

The basement currently has a toilet (by itself) and a utility sink on the other side of a wall next to the toilet. The sink trap goes into a drain pipe that goes through a wall and into a pipe -- the toilet and sink seem to share a vent? The washer also drains into this sink. I don't believe there is any rough-in for a tub/shower and I have no idea how the toilet connects to the sewer under the floor.

Here are my questions:
1) Is it feasible to add a tub to this existing set-up?
2) If so, how close does the tub drain have to be to the existing vent?
3) Is it realistic to think that I can move the toilet drain at all? My preferred option would be to move it a foot or two over (to the left, in this picture) and several inches away from the wall with the toilet turned 90 degrees. My second choice would be to move it just away from the wall a few inches because I think it is too close to finish the wall, currently.
4) Can I connect a Laundry drain to this setup? I'd like to get rid of the utility sink and have the washer go to a standpipe somewhere.

I have seen Speedball1 post this several times but I don't fully understand it as it relates to my setup. I suspect I have old or out-of-compliance plumbing?
"Toilet connects to sewer main. The toilet wet vents through the lavatory vent. Lavatory connects to toilet drain and runs a vent out the roof or revents back into a dry vent in the attic off the top the stubout tee. 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,( unless local codes call for individual vents) but also The Standard Plumbing Code Book."

Here's a beautiful picture:

[speedball1]

Here are my questions:
1) Is it feasible to add a tub to this existing set-up?
2) If so, how close does the tub drain have to be to the existing vent?
3) Is it realistic to think that I can move the toilet drain at all? My preferred option would be to move it a foot or two over (to the left, in this picture) and several inches away from the wall with the toilet turned 90 degrees. My second choice would be to move it just away from the wall a few inches because I think it is too close to finish the wall, currently.
4) Can I connect a Laundry drain to this setup? I'd like to get rid of the utility sink and have the washer go to a standpipe somewhere.

1) Yes
2) Unless you plan on adding a separate vent for the tub it will connect to the lavatory drain line where it will be wet vented.
3) Once the slab's opened up and the drainage exposed you may cut into the toilets drain line with a 45 degree bend and reposition and turn it any way you wish.
4) If you're asking if you can install a washer stand pipe to replace a laundry tray the answer's yes. Make the stand pipe 2" over the flood rim of the washer. The water will extend up the wall to 1/2" drop eared ells where 1/2" boiler drains will be installed.

I have seen Speedball1 post this several times but I don't fully understand it as it relates to my setup. I suspect I have old or out-of-compliance plumbing?
"Toilet connects to sewer main. The toilet wet vents through the lavatory vent. Lavatory connects to toilet drain and runs a vent out the roof or revents back into a dry vent in the attic off the top the stubout tee. 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,( unless local codes call for individual vents) but also The Standard Plumbing Code Book."

What part don't you understand? The toilet's already connected to the main and you can pick up the lavatory off either vent although I would recommend the left hand vent as the other will be picking up the washer. Your tub drain will connect to the lavatory drain line where it will be wet vented by the lavatory vent. Good luck, Tom

[jameslrice]

Wow! Thank you for your quick reply.

What part don't you understand? The toilet's already connected to the main and you can pick up the lavatory off either vent although I would recomend the left hand vent as the other will be picking up the washer. Your tub drain will connect to the lavatory drain line where it will be wet vented by the lavatory vent. Good luck, Tom

Ok, I think I was confused because it would seem like there were two drains and vents when there needed to be only one if the lav (or in this case utility sink) can wet vent the toilet. Thank you for clarifying.

One follow-up question -- hard to tell from the pic but from my eye it appears that the left hand vent (2.5") is larger by a half inch than the right hand vent (2"). I'm guessing the left is the vent for the toilet drain? Would it be wiser to connect the washer standpipe to the left vent since the discharge from a washer is higher volume?

The resulting design would have:
Lav connected to right hand drain
Tub drain connected to lav drain line and wet vented by lav
Standpipe connected to left hand drain and vent
Toilet connected to the main and wet vented by washer?


Also, is there a limit to how far I can have the standpipe from the vent? If I turn this into a full bathroom the washer will likely be several feet away?