Move bathroom sink drain pipe?

[Bommar2]

I’m remodeling a bathroom and need to move the water and drain pipes for the vanity about a foot to the right. The water lines aren’t an issue as I’ve worked with copper pipe before but the drain line seems to be cast iron or something similar. I attached pictures to show what I’m working with. The drain line goes straight through the basement and then up into this bathroom. It goes left to the toilet pipe and vent. Can I just turn that pipe in the middle and run the line right through the stud and then out where I need it? Or any other advice? I’ve never worked with cast iron so I’m pretty clueless here.

 

[Plumber69]

You have cast below and steel pipe above. I'd take a grinder and cut the tee out. Replace it with 2 clamps a new tee and go thru the stud and 90 out

 

[Sponsor]

 

[Reach4]

You may want to improve the clamping holding the weight of the vent line before cutting. Maybe it is supported enough already, but check.

 

[Bommar2]

You have cast below and steel pipe above. I'd take a grinder and cut the tee out. Replace it with 2 clamps a new tee and go thru the stud and 90 out

Thanks. Just a couple more questions as I've never worked with steel or cast iron. How is the tee actually connected? Do I just cut it anywhere on the tee and slide it out? Or do I just cut above and below the clamps that are on there now and then connect a new tee? And then would I go with a steel tee or pvc? And depending on that answer, what type of clamps would I go with? I see cast iron to PVC compression donuts and I see some clamps that can be used with cast iron.

Sorry for all the questions - I've only worked with PVC and copper so I just want to make sure I don't screw anything up!

 

[Bommar2]

You may want to improve the clamping holding the weight of the vent line before cutting. Maybe it is supported enough already, but check.

Thanks. I will double check that before I cut - it seems pretty sturdy but I'll make sure.

 

[Reach4]

How is the tee actually connected? Do I just cut it anywhere on the tee and slide it out? Or do I just cut above and below the clamps that are on there now and then connect a new tee?

Those are not clamps; they are hubs cast into the cast iron sanitary tee.

I think Plumber69 was saying he would cut through above and below those hubs, and insert a new plastic tee plus pipe stubs into the gap. You would use 2 banded clamps such as Fernco Proflex. See https://www.fernco.com/plumbing/shielded-couplings/proflex-couplings You need to figure out the right size. Your top pipe may be "2 inch" galvanized. If that is the case, you would probably select the Fernco 3000-22 or Mission CP-200 to connect between the galvanized and the 2 inch plastic on top of the santee. For the bottom fitting, continue down that page to the table with dimensions. Column A and B are the pipe OD size. C is the length of the fitting. It could be another Fernco 3000-22 that you use there, but it could be something else.

You can use dishwashing detergent as a lube.


It is also possible to dig out the hub on the cast iron, and put PVC into that. You would then use a lead-replacement such as Soil-O to fill and seal. That might require oakum too. I don't know. That would be a slower process, and you would have to do more research. You probably don't want to do that.

 

[Bommar2]

Those are not clamps; they are hubs cast into the cast iron sanitary tee.

I think Plumber69 was saying he would cut through above and below those hubs, and insert a new plastic tee plus pipe stubs into the gap. You would use 2 banded clamps such as Fernco Proflex. See https://www.fernco.com/plumbing/shielded-couplings/proflex-couplings You need to figure out the right size. Your top pipe may be "2 inch" galvanized. If that is the case, you would probably select the Fernco 3000-22 or Mission CP-200 to connect between the galvanized and the 2 inch plastic on top of the santee. For the bottom fitting, continue down that page to the table with dimensions. Column A and B are the pipe OD size. C is the length of the fitting. It could be another Fernco 3000-22 that you use there, but it could be something else.

You can use dishwashing detergent as a lube.


It is also possible to dig out the hub on the cast iron, and put PVC into that. You would then use a lead-replacement such as Soil-O to fill and seal. That might require oakum too. I don't know. That would be a slower process, and you would have to do more research. You probably don't want to do that.

Thank you very much. So bacially I will just cut above and below the hub, and insert something like this (https://www.homedepot.com/p/2-in-PVC-DWV-All-Hub-Sanitary-Tee-C4811HD2/100343584). Then insert some pvc stubs to fit flush against the cast at the bottom and the steel at the top and secure with the banded clamps you linked. Then just pvc out of the tee and through the stud and then a 90' out toward the bathroom to connect to the drain .

 

[Reach4]

So bacially I will just cut above and below the hub, and insert something like this (https://www.homedepot.com/p/2-in-PVC-DWV-All-Hub-Sanitary-Tee-C4811HD2/100343584). Then insert some pvc stubs to fit flush against the cast at the bottom and the steel at the top and secure with the banded clamps you linked.

I think that's it. I cut my steel using a reciprocating saw. It was tedious. The cutoff wheel would be faster, but you would need a larger angle grinder than mine to cut "2 inch" pipe.

Then just pvc out of the tee and through the stud and then a 90' out toward the bathroom to connect to the drain .

I think that 90 should be a long sweep. I am not sure that is required, but it is better even if it is not required.

I am not a plumber. I have replaced 2 cast iron santees using those banded couplers. I took about 50x more time than a plumber would have.

 

[Bommar2]

I think that's it. I cut my steel using a reciprocating saw. It was tedious. The cutoff wheel would be faster, but you would need a larger angle grinder than mine to cut "2 inch" pipe.

I think that 90 should be a long sweep. I am not sure that is required, but it is better even if it is not required.

I am not a plumber. I have replaced 2 cast iron santees using those banded couplers. I took about 50x more time than a plumber would have.

I will probably just rent a cast iron cutter from Home Depot this weekend but I did have one more question. Will the vent line work properly if it’s not directly above where the sink is draining. Like in my situation where I tee off the line won’t be vented from that point until the spot I come out at the sink. I really don’t know all the ins and outs of vent lines, so I didn’t know if that would be an issue. Since it’ll only be moving about 12 inches I figure it’ll be fine but I wasn’t sure.

 

[Bommar2]

Thanks for the help everyone. Got it all hooked up and it seems to be working fine. Ran water down it for about 5 minutes with no leaks.