Drain Vent Stack Tee Sheared Completely

[suzyq2626]

I have just discovered a leak in my exterior wall that has been going on for who knows how long. The source has been found at the Tee fitting where my kitchen sink meets the Vent/Drain Stack in the wall. The Tee fitting was completely sheared where the horizontal pipe meets the vertical. Therefore the waste water from my kitchen sink has been draining into my wall. This vent stack goes directly up through the roof. The roof was replaced 4 years ago. The piping is ABS black plastic pipe, 1-1/2" dia. The house and piping is 17 years old.

We are trying to figure out what could have caused the fitting to completely shear apart at the horiz/vert. junction like that. We have never had any drainage issues or signs of blockages, and there has never been any work on the drain pipe under the sink, or elsewhere. The only work ever done in this area would be the roof vent stack flashing replacement.

Any suggestions?

 

[Terry]

Sometimes earthquakes will break the pipes like that. Other times the wood studs dry and shrink in height causing stress to the fittings.

 

[Sponsor]

 

[hj]

I have had it happen many times, and no earthquakes. It just happens, possibly because of stress, although the tees always seem to be "free/loose". Possibly excess cement weakened the connection point, but it is just a supposition.

 

[suzyq2626]

Sometimes earthquakes will break the pipes like that. Other times the wood studs dry and shrink in height causing stress to the fittings.

We don't have earthquakes in our area generally. Had a very minor 4.0 earlier this year, but the leak has been occurring since way before that.

I suppose the wood studs movement could be a cause, though the house is 17 years old.

What are your thoughts on the roofing work at the vent flashing possibly causing this? My roofer (who replaced the roof 4 years ago) thinks it would not be possible for movement or force on the vent stack to have caused this. I am leaning towards this being the most likely cause, but am looking for opinions on likelihood.

 

[suzyq2626]

I have had it happen many times, and no earthquakes. It just happens, possibly because of stress, although the tees always seem to be "free/loose". Possibly excess cement weakened the connection point, but it is just a supposition.

The break was not at the connection point between pipe and tee fitting, but within the fitting where the horizontal part of the Tee connects to the vertical part.

The tee also was not free or loose at all from the pipes.

Thanks for your suggestions.

 

[hj]

same thing, and by loose, I meant it was not cemented into the wall or fastened in such a way that any stress would break it.

 

[suzyq2626]

same thing, and by loose, I meant it was not cemented into the wall or fastened in such a way that any stress would break it.

So maybe the vent stack is strapped to the wall, and the horizontal drain run is only running through holes in each stud, therefore there is some movement allowed.

We tested the vent stack movement, and when rotating and moving the vent pipe from inside the kitchen wall, it moves up/down, side-to-side accordingly on the roof -- this would mean what?

 

[Terry]

Roofers normally install the roof flashing, and it would be surprising if any damage could have been done by a roofer.
ABS is pretty tough stuff. I have seen it crack from stress over long periods of time. It gets old. I had a pair of plastic ski boots that were old, and one Spring day, both ski boots broke. I had to rent boots that day. Not just one boot, but both, and that was just walking in them to get my lift ticket for the day.

 

[hj]

It means that it just snapped and you need to replace it.

 

[Reach4]

I suspect stress was applied the last time somebody had worked on the kitchen drain.

 

[suzyq2626]

I suspect stress was applied the last time somebody had worked on the kitchen drain.

Nobody has worked on the kitchen drain in at least the last 5 years, as that is how long we've lived here and no one has touched it. The vent stack attached to the drain was worked on 4 years ago when the roof flashing was replaced. The roof flashing is located approximately 8 feet above the drain tee connection.

I'm meeting with my roofer tomorrow morning to see what he says.

 

[Reach4]

Maybe somebody worked on it. Broke it. Whoops... What if I just jam it together, or maybe add some glue and jam it together. Maybe no body will notice before I get this house sold.

I am not a plumber. My story is just a theory.... I never broke a plastic sanitary tee, myself, but I did manage to break a cast steel or iron sanitary tee with too much torque, or at least expand the crack. I should have gone into the wall to fix it earlier, but I kept trying to fix with a lesser action.

 

[hj]

The ones I have repaired "just happened". NO ONE worked on them or applied any stress on the pipes or fittings.