Hi guys,

I live on the 3rd floor condo unit and it looks like all the dirty water from my neighbors on the 4th floor end up in my kitchen sink constantly. I told the management about the issue but they are not doing anything beyond promising its repaired and in few weeks same thing happens again.

I got a test plug but noticed few times when I come home and open it there is a standing water all the way up which slowly drains by the morning so when I call the management they look at me as if I am a crazy person constantly complaining.

I am leaving for a week and put the test plug in to prevent any overflowing. I never left for such a long time so I am concerned if there is a drain blockage again and the water flows into my kitchen sink (which is now plugged with a test plug) where will the water go?

It will back up the pipe towards the guy on the 4th floor, perhaps reach him. The association needs to send someone to the roof with a snake to clear out the pipe. If you're ambitious you can plunge it yourself or try some of the drain cleaning stuff, such as Green Goblin. Skip the caustics.