I'm installing a new closet bend and a small section of 3" pipe going out to the main stack. My bend currently comes right up against a joist. So I don't really have much clearance on that end - and of course I don't have any clearance on the stack end. I have to cut the current stuff out, install a coupling, section of new pipe, then the bend (the bend has to come up in the same spot). So how do I get the same length/measurements in a space with no clearance? It's not like I can bend the coupling or pipe.

Can you post a photo ?

Are you saying that you don't have enough space between the bend and the stack to put a coupling and rejoin the pipe? Have you cut anything yet?

If you lack enough space to connect your new closet bend with existing pipe - then, use Flex Seal coupling. It is flexible and you can sleeve it on one end and then push it over onto the other one. With a bit of effort, you can even sleeve it over the hub end of your fitting.

I've tried to diagram it here - this is an overhead shot. The blue stripes are floor joists (2nd floor bath). The vertical orange pipe is the main stack. The short orange piece is a 3" section that goes through the joist over to the current bend. The "L" piece is the existing 90 that is in place. It butts up right against the joist as you see.

About the flex couplings - I'm not a pro, so I don't know - but I just don't really like the idea of my "stuff" going through those couplings that are just tightened with screws - the ABS cement sounds better to me.

About the flex couplings - I'm not a pro, so I don't know - but I just don't really like the idea of my "stuff" going through those couplings that are just tightened with screws - the ABS cement sounds better to me.
I don't like rubber "flex" connections either. But all mechanical connections don't "flex" If you don't have the room to prime and glue in a ABS Coupling I would use a shielded coupling,(see image) to join the two together. Good luck, Tom

Sure, ABS glued coupling is the best connection - if you have the luxury of space, of course. But sometimes we have to go to plan "B" if we don't want to cut into floor joists. Can you use type of coupling that Tom suggested ?

Here's a picture - can anyone see a way around using a shielded coupling?

You haven't say why you are doing this or what you wish to accomplish. Looks like you have plenty of room to cut pipe and reconnect with coupling.

How about telling us what you are doing.

My new floor is going to be a decent bit higher than the old floor was, and I didn't want to go to all this bathroom trouble and put the cheapo $5 flange spacers in. I got a new flange with stainless steel ring (the current is just ABS), and I was going to set it correctly on the finished floor. To do that I need to cut out the bend and put in a new closet bend.

Unless that pipe is awfully short, you won't have any trouble bending it 1 1/2" to left to make up for what you lose when you cut the bend off.

If you can't move it, cut the pipe right about where the plug of you saw lays, install coupling, short pipe and closet bend.

can anyone see a way around using a shielded coupling?
Sure! You simply undo the bands on the coupling, wrap it around the pipe and retighten the bands. Good luck, Tom

I think I did pretty well, but I'm a bit paranoid, since a leak is what got me in this mess. I put in a new closet bend (to get the height back up to the finished floor right), and joined it in with a coupling... I originally thought I wouldn't have room to shove this all in (see here: https://www.askmehelpdesk.com/plumbing/installing-new-bend-section-pipe-251195.html ). But I had a little give in the pipe and it went fine.

My leak test was to take a pretty large bowl and pour all the water down. No leaks. Is this a sufficient test? If it's not leaking now does that mean it won't leak forever? Is there any better way to simulate a toilet flush?

There is some pooling at the joint where the bend meets the pipe, and I'm assuming where the short section of pipe meets the coupling and then the long section (old) pipe. This pooling is pretty much unavoidable correct? I've included a picture.

My leak test was to take a pretty large bowl and pour all the water down. No leaks. Is this a sufficient test? If it's not leaking now does that mean it won't leak forever? Is there any better way to simulate a toilet flush?
There is some pooling at the joint where the bend meets the pipe, and I'm assuming where the short section of pipe meets the coupling and then the long section (old) pipe. This pooling is pretty much unavoidable correct?


I've merged your past posts to make reading easier. You have a leak that must be repaired. Any "pooling" at all is unacceptable. The first thing I would try is paint all around the coupling joints with ABS Primer and slather ABS Cement all around both joints and let it set up and cure in. After the glue drys pour two or three buckets of water down the closet bend. Take some toilet paper and run around the joints. If you see the slightest bit of moisture cut everything out and try again. You did prime everything didn't you? Good luck, Tom

From the last photo I can see that you have adequate slope. The "pooling" is there because the short 3" pipe nipple is not pushed all the way inside the Hub of your closet bend. Water stands in the Hub. It is a weak joint.

Speedball - there's no pooling on the outside - I already did a good test with paper towel and there was no moisture. The pooling is inside - I reached down the bend after one of the tests and felt where the 3" pipe meets the hub. I pressed it in pretty good. You're saying that all pipes should meet all the stops?

Speedball - there's no pooling on the outside - I already did a good test with paper towel and and there was no moisture. The pooling is inside - I reached down the bend after one of the tests and felt where the 3" pipe meets the hub. I pressed it in pretty good. You're saying that all pipes should meet all the stops?
All fittings should be tight but if you have no leaks on the outsaide I'd say you were good to go. Good luck, Tom