unit upstairs causing back up in my sink

[killerbees]

Hi, I've been reading various threads on these forums and find them very informative. I have an issue I am trying to diagnose (I have 0 plumbing experience).

I recently moved into an apartment building. I am on the first floor of the building, there are 5 floors above me. About once every other day the sink in my bathroom spews out "back up". The splash pattern looks like it comes out in a spurt and leaves behind a lot of residue. Frequently there is foam in the back up.

My guess is that a unit above me has a dishwasher (or garbage disposal unit, but this is less likely since they are not allowed in our building) connected to the same drain pipe and it is installed without a vent thereby causing pressure in the drain pipe which relieves itself by spewing out of my sink. I have attached pictures of the backup. The building's plumber says he doesn't know how to diagnose this issue. Does my theory sound likely? Should I see if the super or management company can arrange to run the dishwashers in the units above to see if that is indeed what is causing this?

Thank you in advance for your help!

 

[Jerome2877]

No it is a partial blockage in the line below your floor. When there is enough volume from above (maybe a DW or maybe 2 or more sinks running) it will back up and since your just above the blockage it comes up your sink.

 

[Sponsor]

 

[killerbees]

No it is a partial blockage in the line below your floor. When there is enough volume from above (maybe a DW or maybe 2 or more sinks running) it will back up and since your just above the blockage it comes up your sink.

Makes sense. Thank you. It sounds like that should be fairly easily to resolve. Appreciate your help.

 

[hj]

A first floor sink is ALWAYS subject to possible "suds explosion" if the sink is connected to the system within the "suds pressure area". It is caused by the soap and water mixing with air as it flows down the pipe, and then bursts into suds when it hits the turn at the bottom of the pipe to go horizontal. BUT, it would be more common with a kitchen sink than a bathroom one, unless the bathroom sinks have their own "stack". If that is the cause, then cleaning the drain MAY minimize or eliminate the problem, but it WILL come back later.

 

[killerbees]

A first floor sink is ALWAYS subject to possible "suds explosion" if the sink is connected to the system within the "suds pressure area". It is caused by the soap and water mixing with air as it flows down the pipe, and then bursts into suds when it hits the turn at the bottom of the pipe to go horizontal. BUT, it would be more common with a kitchen sink than a bathroom one, unless the bathroom sinks have their own "stack". If that is the cause, then cleaning the drain MAY minimize or eliminate the problem, but it WILL come back later.

Interesting. My unit is a different configuration than the ones above me so my bathroom sink lines up with kitchen sinks above.

Is a suds explosion capable of pushing out heavier residue like that shown in the first picture? I wouldn't mind it so much if it occurred every once in a while. This happens, on average, once every two days, with two occurrences in one day some times.

Thank you.

 

[hj]

It will dislodge any loose material and carry it with the suds.

 

[killerbees]

It will dislodge any loose material and carry it with the suds.

Thank you all. The building's plumber agrees with the comments here i.e. it being a suds explosion made worse by clogging lower down. It's unlikely to be resolved any time soon but at least I have some idea about why it's happening. Much appreciated.

 

[Kreemoweet]

"Unlikely to be resolved any time soon"? Really? This is clearly an "unsanitary" condition, and I do believe that building owners are responsible to rectify such conditions immediately,
maybe even in New York. Where I live, a phone call to the Public Health Department about such a thing would result in quick pressure being brought to bear on the landlord. That
black stuff in your sink is clearly not "suds", and in fact could be anything at all.

 

[killerbees]

"Unlikely to be resolved any time soon"? Really? This is clearly an "unsanitary" condition, and I do believe that building owners are responsible to rectify such conditions immediately,
maybe even in New York. Where I live, a phone call to the Public Health Department about such a thing would result in quick pressure being brought to bear on the landlord. That
black stuff in your sink is clearly not "suds", and in fact could be anything at all.

Good point. The plumber went to the basement to look for the pipe to try and figure out how clogged up it is and couldn't find it so it's in the walls i.e. in concrete. He said he will start with snaking the drain from our unit to see if the problem goes away. He doesn't think it will but thinks its worth a try before tearing into any walls. He also mentioned putting a valve between our drain and the main pipe so the flow only goes one way but I don't like that solution because at some point the pressure is going to be too much and we will have bigger problems. I'll wait for him to snake the pipe and if that doesn't help, I'll have to push harder. Thank you.