Basement w/ toilet- DWV questions to add sink and shower?

In my 1917 Bungalow near Chicago, IL there was a toilet in the unfinished basement. I have since finished the basement and are now getting ready to tackle the bathroom. I want to add a sink and a shower to this space and have a few questions.

I removed the toilet and did some exploratory digging and found the basement closet flange and a 1-1/2" galvanized vent connected to a fitting along with a cleanout and the main floor's bath DWV going into a 6" clay tile leading to the street.



I would prefer not to mess with the clay tile so my questions are as follows:

Would it be correct if I cut the existing closet flange at the bend, add a fernco fitting and tie in new PVC or ABS DWV system for new shower, new sink, and to relocate toilet, with venting for each to tie in above the flood rim of the sink into the 1-1/2" galvanized? If so, being that this will be horizontal and under concrete, should I use sanitary tee or wye?

Thank you!

Last I knew Chicago required cast-iron for all new work below grade. You are only allowed to transition to PVC above the floor.

If your layout allows, removing the closet bend and extending that section for your new line may be the only way to avoid major work.

Chicago code only allows cast iron underground and you will need a two inch vent for the toilet. That being said if you want to use PVC because of the cost that's up to you. However it wont pass inspection if there is one. Like . Also keep in mind that in Chicago you have to use 4'' for underground. The fitting often used around here to pick up a toilet thru an underground is a 4" combo with 2'' side inlet. A combo is basically a wye with a 45 on it and the side inlet will be for the vent.

Thank you very much gents! Your replies offer great insight. I'm actually just outside of Chicago in Berwyn but I assume that the same code applies...

Depending on where you put the sink and shower, you may need to do more. You may not have enough slope with the p-trap for the shower to actually have it drain properly with what you have without redoing a bit more so it can enter lower. You may not find an equivalent toilet elbow in pvc. Last, you cannot assume your codes are the same as Chicago's.

are you sure that is 6" clay and not 4", and you might be better off having a plumber cut the clay and install the new drainage properly, rather than try to fit everything, including all the necessary vents, into the closet bend.

hj said:

are you sure that is 6" clay and not 4", and you might be better off having a plumber cut the clay and install the new drainage properly, rather than try to fit everything, including all the necessary vents, into the closet bend.

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6" clay drains are very common in the Chicago area. The last two post do make a good point. You might not have enough room to run new lines with proper pitch coming out of the sanitary tee.

6" clay drains were common in the Chicago area, but usually outside the buildings. I saw only 4" clay inside the buildings, especially in residences. The parallax makes it difficult to tell whether that is a 4" closet bend or a 4x3 one, which means I have nothing as a reference to compare the various pipe sizes with.

"6" clay drains were common in the Chicago area, but usually outside the buildings. I saw only 4" clay inside the buildings, especially in residences. The parallax makes it difficult to tell whether that is a 4" closet bend or a 4x3 one, which means I have nothing as a reference to compare the various pipe sizes with."


Some areas in Chicago have 6" all the way inside, my house for example has 6". A couple of years ago I decided to relocate the plumbing in the basement what I found was a 6" clay house drain with an improper transition to PVC. The top side of the clay was smashed in, PVC was stubed into the hole and finished off with a water tight mortar joint. However like you said its impossible to determine the pipe size from the picture.

From what I see you have to cut into the clay pipe to get enough fall for your proposed hook-up. Clay is not hard to cut; if you can borrow a pair of snap cutters they work like a charm. luck.

I'm pretty sure that what I have is 4" cast going into 6" clay...the way that I came to that conclusion was by measuring the o.d. an resesarching online for i.d. based on that o.d. measurement...the i.d. of the closet flange is 4" and it is cast iron...thank you all for your help, I measured from the finished floor to the top of the 4" cast iron closet bend that I was thinkning of using to tap in and it would be really tight to get the proper slope...I either raise the floor by a few inches and sacrifice the head room or contract out the DWV rough-in...THANKS AGAIN to all for your help!