Cutting and extending ABS

[hans_idle]

In the picture below, I have 2 ABS "T" pipes. One is on the left, with the upper end going to the roof vent. The right-hand "T" is for a sink drain, and then it continues a few feet to the right for another sink.

I need to move the right-hand "T" in the picture to the right about 20" because I'm moving my cabinets and sink over. But if I cut the ABS between the 2 "T" pipes, then I won't have any pipe to put a coupler onto. If there was an inch or two between the "T" pipes, then I could attach the couple to that, but they are right next to one another.

What is the best way to separate and repipe this? I suppose I could cut out both "T" pipes along with a few inches on the vent stack, then put couples on the vertical pipe along with a "T", and then run the line to the right.

Oh, and the insulation was ripped before I got to it

Thanks!

-Hans

[Lakee911]

I would enlarge your hole and cut back furthur on the pipes to give you something to work with. You could maybe get a fernco over the fitting on the vent side? Maybe someone else can chime in with another idea too. If you open it up and just cut back on the pipes furthur, this will also allow you to repair the sloppy job with the vapor barrier too.

[hans_idle]

Thanks.

Along those lines, I'll have to replace the majority of the vapor barrier that was behind the sinks. What's the proper way of putting it in? Does the pipe go on this side of the vapor barrier, or is the barrier meant to be pulled away from the insulation and then stapled down overtop of the pipe and insulation? The key, obviously, is not to rip it, which most of it is.

[jimbo]

You either have to go further back, replacing more fittings than you planned, or use a drill called a RamBit to get the pipe remnant out of the hub.

Actually, with ABS, it is not impossible to just slice the pipe inside the hub with a hand held hacksaw blade, or dremel, and peel out the pieces. ABS does not weld the same as PVC, and often you can get away with this

[Herk]

Laying a tee on its side is illegal everywhere I've plumbed. So it was wrong from the get-go. I guess if you have no code where you live, this might work. On the other hand, it is legal to have a single elbow and trap and then use a continuous waste pipe, like a kitchen sink, to connect two basins.

[hans_idle]

Herk,

Yes, we have codes here (in new jersey), but as I'm finding out, my master bathroom is a bit of a mess when it comes to the plumbing and electrical compliance. Or at least it was a mess and now I'm fixing it the way it should be.

I did not know you couldn't lay a T on it's side. How do you plumb a situation like this? Is there something to use other than a T, or do you run 2 lines off of the vent stack, one for each sink? Or is there some other way to do it?

Thanks!

[Winslow]

it is also illegal to put 2 traps on one trap arm.

[hans_idle]

Hmmm. Interesting. So what is the proper way of plumbing the drain pipes for 2 sinks that are 4 feet apart? should the drain line come up BETWEEN the 2 sinks and then T off to the left and right? Is there any other configuration that would work?

[Herk]

Yes, the proper way would be to come up between the sinks and use a double fixture fitting, which has been discussed elsewhere on this forum.

[hans_idle]

Just as a follow-up, here's a picture of how the drains look now. Both sink drains connect to the vent/drain stack on the left side of the picture (partially visible in the open floor).

It seems that there are a number of problems with this setup.

[hans_idle]

If I want to plumb this the "right" way, it looks like I have a couple of decisions to make. The drain and vent are on the extreme left of the bathroom. In order to move the drain/vent to the center of the 2 sinks, I have couple of options:

1) Notch/bore the floor joists (4-5 of them) to run the ABS line to the right through the floor, then up between the 2 sinks in the wall and into a cross-T. The vent line would continue straight up into the attic, and then elbow back to the left to attach to the vent that is in the roof.

2) Keep the existing drain line in place in the wall on the left of the sinks. bore holds lower in the studs to bring it over to the center of the sinks. Then go up, use a cross-T to split to the 2 sinks, and then vent into the attic.

Option #2 differs only in that there are more holes in the studs and none in the joists. Is there any code that indicates NOT to bore the same stud twice? I'd be boring some of the studs twice; once for the drain line to the cross-T to move it to the center and once for the actual drain to the sink.

If I go with option 1, what is better: notching or boring? I have 2x10 or 2x12 joists (don't recall right now), and I'd be running 1.5" ABS.

I saw an example elsewhere on this site (in a PDF file) of how to properly setup the drain lines. It indicated that 1.5" ABS would be fine for going into the cross-T. That would at least limit the size of the notches or holes I have to make.