I'm remodeling a bathroom and mistakenly did my drainage using pvc pipe. My house had ABS, and we used some of the ABS that we cut out together with the PVC. This was all glued together with PVC primer and cement.

I didn't realize that the black pipe was not pvc until tonight when I was looking into drains. The pipes aren't leaking, but I've read you shouldn't mix the two, especially not with pvc cement. So, should I rip out the new drainage and put in all ABS? Or will it be OK to leave as is?

Some years back our area had a ordinance that forbid commingling PVC and ABS but when All Purpose Glue and Primer came on the market it was OK. However, If you do commingle use a all purpose glue and primer. The reason that you should use the correct glue and primer id that the correct glue will make the two surfaces melt and weld to one another. If you just go back and use All-Purpose Glue on the joints that converts to PVc from ABS you'll be just fine. Good luck, Tom

Quote:

---

Originally Posted by speedball1

Some years back our area had a ordinance that forbid commingling PVC and ABS but when All Purpose Glue and Primer came on the market it was OK. However, If you do commingle use a all purpose glue and primer. The reason that you should use the correct glue and primer id that the correct glue will make the two surfaces melt and weld to one another. If you just go back and use All-Purpose Glue on the joints that converts to PVc from ABS you'll be just fine. good luck, Tom

---

Can I just sand the pvc cement off, or do I need to use a new piece of pipe?

Roughing it up with sandcloth is the same as priming it. Sand it down and reinstall using the proper glue. Good luck, Tom

I can't pull these the pvc pipes and the abs pipes apart. I guess I could saw them apart. I put some together with the solvent I used to see if I could get them apart. I beat them against some cement blocks and still couldn't separate them. Are you sure I need to?

I am confused, have you already glued the pipes together, it sounds that way. Once you glue two together you will not get them apart and expect to reuse that same end.

If you have glued them all together then Bob's correct. They just don't pull apart. Decision time! If this happened to me I would close off all openings and run a test , either water or air, on what I had done. If your work holds a static test then I could get the correct glue and primer abd complete the job. Good luck, Tom

I was told since the pvc solvent doesn't react with the abs that I should just be able to pull them apart with moderate force.

Yes, I think there's some confusion here. All of the work is done, and all of the drains work without leaking. So the choice is to rip it all out and do it again or leave it. To help out, I put some pics up here:


Index of /bathroom/during/plumbing

Tell us all you can about what is written on the can of glue you did use. Is it called an ALL PURPOSE GLUE?

No, it is the regular oatey PVC solvent that comes in the pack with the primer.

Close off all openings and fill the roof vent. Let it set for 8 hours and if you don't have any leaks I would say your job's tight. Good luck, Tom

You are in a tough spot, this glue doesn't weld ABS but does weld PVC. You may have a good weld but it would be luck so try Tom's test to see if its safe. If I were doing this for pay I'd be cutting out that joint and not taking the chance of a leak now or down the road. All Purpose Cement will weld both ABS and PVC.

Please excuse the noobness of this question, but how can I fill the roof vent without the water draining out? These pipes connect to the other drain pipes for the house, so I'm not sure how I could close off all of the other ways out/down?

Hello If you used primer and pvc glue on pvc to abs then the two will fuse together, but this is not the proper use of glue and primer. However abs glue will not work on pvc and you could easily break the joint apart. To end all confusion just cut the section you put together out and redo it with the same plastic that is on the original plumbing, using the proper glue. Goodluck-------- zeke

Although the best thing would be to rip it out, that's going to be a lotta work. Will it work the way it is now? You'll never know until you put your work under a water test. Let us know if it held water over night. If it did I think you'll be good to go. Tom

Speedball, not sure if you saw my comment above, but how would I do this?