How to extend 4" Main DWV when there is no room on the existing pipe

[winky10]

I am remodeling my home and need to tie a 3" DWV into my existing 4" main. The problem is that there is no place to tie into that I can see. The easiest thing for me to do, in order to incorporate all of the plumbing, is to extend the Main another 20 ft so that it can pass under central air ducting, allowing me to drop 3" lines into it at various places. Can anybody suggest a way to do that? The photos attached should give you an idea of what I''m looking at. The existing 3" lines would be replaced/moved. I know that using the cleanout to extend the pipe is prohibited, so I'm not sure what to do, given that the current fittings take up ALL the room. (Please ignore the electrical cable and sloppy supply PEX. The crawl space has since been insulated and encapsulated and the wires and PEX properly secured).

 

[FullySprinklered]

Fitting to fitting, no pipe. Not unusual but always unwelcome.
Far be it from me to suggest that you screw a male adapter into the cleanout and proceed from there. It's not allowed as you pointed out. I probably wouldn't even do that at my house.
Some drains are glued together with more care than others. I don't see any purple primer there. Some fittings are put together with a quick swipe with the glue, some get more careful attention; rolling the dauber around the pipe and in the fitting a couple of times and pushing them together with a quarter turn twist.
If your original installer was a slack-jawed heathen, and he was stingy with the pvc cement, you might be able to peel apart one of the joints and build back your new wasteline from there. The attractive aspect of this approach is that you have several joints to practice on to get it right.

 

[Sponsor]

 

[Terry]

You could cut out the cleanout fitting and use a RamBit to drill out the fitting.
Extending can be done, just remember to install a new cleanout when done.

Or, you could use a male adapter to extend there, and again, you would then have plenty of room to add a wye or other fitting for a cleanout.

 

[hj]

quote; Far be it from me to suggest that you screw a male adapter into the cleanout and proceed from there. It's not allowed as you pointed out.

It was already done once between the Y and the sanitary tee.

 

[winky10]

You could cut out the cleanout fitting and use a RamBit to drill out the fitting.
Extending can be done, just remember to install a new cleanout when done.

Or, you could use a male adapter to extend there, and again, you would then have plenty of room to add a wye or other fitting for a cleanout.

I think that's the way to go. I ordered the Ram bit, and plan on cutting the main just behind the 3" Wye, and reaming it out. That will eliminate the previously installed threaded connection as well. Hoping all goes as planned, because if that doesn't work, it's going to get expensive. And I'll be without plumbing for a while. Not looking forward to that. Fingers crossed.

Any advice on using the Ram Bit? Looks pretty straightforward, but that doesn't mean foolproof.

Thanks for the replies.

 

[Jadnashua]

On a pipe that big, you'll probably need a higher powered drill bit than a typical homeowner's one.

 

[Cacher_Chick]

Not having much need for a 4" rambit, it looks like the pipe is not far below grade, so I might have cut it off outside and put a new stick through the wall. The existing connections would be very easy to restore.

 

[Themp]

In your last picture there is a white contraption hanging down with a clean-out plug at the bottom. The blue bucket looks like it is under it. What is that for?

This thread has been good for information on how you should not use a clean-out with a male threaded adapter for adding to the sewer line. But I did read one thread on the internet(actually might have been this site) where the person took PVC cement and melted the threads so that they would not be a catcher. Since you already have one, do it again and melt both and be done with it. I have had to mess with my sewer lines and I have been amazed at the PVC joints that have a large protrusion of PVC cement sticking up(to much PVC glue was used) and it never seems to have caused a clog. Actually junk seems to collect on the protrusion and smooth things out.