Internal coupling for vertical PVC sewage pipe?

[Haneyeam]

Hello! I have a 4-in 3-in PVC pipe descending through an external wall from two bathrooms upstairs. We found a leak after moving into my new home and my real estate agent recommended a plumber who did the fix you see in the picture. I've sat on it a few months while working on other projects.

Problem is, the larger coupling sits nearly 3/4 in out from the joists and pushes the pipe out a bit as well, so drywall won't fit flush.

I wonder if the existing 2 couplings might be removed and replaced with an internal coupling and a new pipe run from the internal coupling to the sewage pipe in the crawl space. I'd appreciate your advice!

Internal coupling example: https://www.acehardware.com/departm...DfuizKw7LlpJLAYJLBBoCVYQQAvD_BwE&gclsrc=aw.ds

Thanks!

 

[Fitter30]

Never have seen a internal coupling for sewage pipe. Pull the insulation heat the pipe up with heat gun push pipe in and hold till cooled.

 

[Sponsor]

 

[Haneyeam]

Yeah, it almost seems too easy. I wondered if waste would potentially get stuck in the pipe by the coupling. I suppose taking a file and tapering the (inner) top end would prevent that from happening.

 

[John Gayewski]

Yeah, it almost seems too easy. I wondered if waste would potentially get stuck in the pipe by the coupling. I suppose taking a file and tapering the (inner) top end would prevent that from happening.

Huh? There are no couplings that make the pipe smaller inside, as it's illegal and against plumbing norms.

 

[Haneyeam]

Huh? There are no couplings that make the pipe smaller inside, as it's illegal and against plumbing norms.

I don't understand your reaction. Did you see the internal coupling I linked?

 

[wwhitney]

That internal coupler it's not for DWV use. There are no internal couplers for DWV use, it is prohibited to reduce the internal diameter.

Cheers, Wayne

 

[Haneyeam]

That internal coupler it's not for DWV use. There are no internal couplers for DWV use, it is prohibited to reduce the internal diameter.

Cheers, Wayne

Thank you. The house actually has 3-inch schedule 40 PVC. It looks like the plumber used a length of DWV for the patch, which could be removed. Regardless, an internal coupling on a 3-inch schedule 40 PVC pipe would still be prohibited because it reduces the internal diameter?

 

[John Gayewski]

I don't understand your reaction. Did you see the internal coupling I linked?

Those are for craft projects. They have goofy non plumbing fittings for black iron piping also.

 

[Haneyeam]

Ok, thank you. They are sold at many online plumbing stores (I am not a pro so you guys are the boss on whether they are reputable and appropriate for sewage plumbing). Another site that sells them: https://www.pvcfittingsonline.com/3-schedule-40-pvc-pipe-inside-connector-s0302-30.html

What I'm hearing is that there is no internal coupling that can repair this pipe to code. If I want to fix the drywall issue in the living room, I need to tear out the wall on the second floor and run a pipe from there to the crawlspace.

I would be very, much, super appreciative of any other ideas!

 

[John Gayewski]

You either fur the wall out or trim the back of the dry wall so it'll fit.

You can also just cut the drywall where the couplings are and mud that area back in. I prefer to leave the paper and some gypsum if possible.

3" fittings don't fit in a 2x4 wall but the pipe does generally a wall that has 3" pipe in it will be made of 2x6 studs. If not you either shim or someone has fun drywalling and mudding.

 

[Reach4]

3" fittings don't fit in a 2x4 wall but the pipe does generally a wall that has 3" pipe in it will be made of 2x6 studs. If not you either shim or someone has fun drywalling and mudding.

OP has 4 inch pipe. In retrospect, 3 inch pipe would have probably been a better choice.

 

[Jeff H Young]

You either fur the wall out or trim the back of the dry wall so it'll fit.

You can also just cut the drywall where the couplings are and mud that area back in. I prefer to leave the paper and some gypsum if possible.

3" fittings don't fit in a 2x4 wall but the pipe does generally a wall that has 3" pipe in it will be made of 2x6 studs. If not you either shim or someone has fun drywalling and mudding.

On new construction Slab homes its always fun to have the responceabilty on ground work of making a 4 inch od fitting fit in a 3 1/2 inch wall LOL . The concrete forms bow etc all depends how framer snaps out the wall, drywallers good ones scarf out a little on the inside of the wallboard

 

[wwhitney]

OP has 4 inch pipe.

That's what the first post says, but looking at the photo, while it's hard to read the text, pretty sure it says 3" PVC.

Cheers, Wayne

 

[Jeff H Young]

I saw that it said 4 inch and ignored it if its 4 inch than its either not a 2 x4 wall or he has bigger problems

 

[Haneyeam]

I saw that it said 4 inch and ignored it if its 4 inch than its either not a 2 x4 wall or he has bigger problem

You guys are right, my error, it is 3-inch pipe.

The coupling pushes out about 3/4 inches, so unfortunately I can't just fur out the back of the drywall. Since the location is close to the edge of the wall, I don't think I can give the drywall a gentle bend either.

I'm considering running a new length of pipe from the PVC coupling to the crawlspace. That would take up less space than the band clamp fitting and maybe I can get a piece of drywall to fit with furring out the back or cutting and mudding.

Thanks for all the responses - much appreciated!

 

[John Gayewski]

You guys are right, my error, it is 3-inch pipe.

The coupling pushes out about 3/4 inches, so unfortunately I can't just fur out the back of the drywall. Since the location is close to the edge of the wall, I don't think I can give the drywall a gentle bend either.

I'm considering running a new length of pipe from the PVC coupling to the crawlspace. That would take up less space than the band clamp fitting and maybe I can get a piece of drywall to fit with furring out the back or cutting and mudding.

Thanks for all the responses - much appreciated!

A regular no hub coupling would also take up less width than that coupling he used.

 

[Reach4]

Is the pipe bowed out?

Is it the center of the shielded coupling that sticks out farthest?

 

[LLigetfa]

Pull the insulation heat the pipe up with heat gun push pipe in and hold till cooled.

First off, is that a waste pipe or a vent pipe? Not sure if code says anything about deforming the pipe to be slightly oval but between scarfing out the backside of the exterior sheeting depending on what type of siding there is along with scarfing out the drywall and making the pipe slightly oval might do it.

I don't know how cold it gets in Virginia but in these parts, we would never put a pipe like that in an exterior wall.

 

[Haneyeam]

Is the pipe bowed out?

Is it the center of the shielded coupling that sticks out farthest?

Yep, the shielded coupling sticks out the farthest. And yes, the pipe is bowed.

A few measurements:
- The studs are 3.5" deep (2x4s).
- The shielded coupling is about 1/2" thick. The pipe and coupling together is about 4 to 4 1/8" diameter.
- The 3" PVC coupling is about 1/4" thick and per Google, should be about 3.5" in diameter.
- The shielded coupling is about 1/2" thick. The pipe and coupling together is about 4.25" diameter.
- The existing 3" PVC coupling is 4" in diameter (external).

So what that tells me is if I (or a plumber/handyperson who is more skillful) eliminates the need for the shielded coupling by running a new PVC pipe from from the PVC coupling to the connection in the crawlspace, it should pretty much solve my drywall dilemma. make it easier to carve out the back of the drywall to fit the

How does that sound?

 

[Haneyeam]

First off, is that a waste pipe or a vent pipe? Not sure if code says anything about deforming the pipe to be slightly oval but between scarfing out the backside of the exterior sheeting depending on what type of siding there is along with scarfing out the drywall and making the pipe slightly oval might do it.

I don't know how cold it gets in Virginia but in these parts, we would never put a pipe like that in an exterior wall.

If I understand your question, it carries waste from the 2 bathrooms on the second floor to the crawlspace. There is a vent pipe that runs from this pipe to the roof (I assume they all connect in the bathroom wall above).

Thanks for the idea about deforming the pipe. In a separate response, I outlined what I think might be a solution.

The house was built in 1987 and I was told that builders (perhaps due to code changes) no longer put waste pipes in exterior walls. We do get cold enough that, for example, several folks I know had burst pipes over Christmas this year because we had temps below freezing for about a week.