Expert: Sharon McCarthy - 11/10/2009

Question
I am writing for advice to fix a kitchen sink glug I have had for a while in our 50-some year old ranch style house. The sink drain which contains a disposal and dishwasher drain leads down to a cellar metal trap and then through a 5.5 foot horizontal copper pipe to the main exit pipe. The roof vent pipe appears free and clear. From the open trap, I have pushed a manual drum snake about 5 feet through the clear horizontal pipe before it gets hung up and stops moving forward. What do you suggest?  

Answer
Dear Stephen,

  Where the horizontal copper pipe "tees" into the main exit pipe, does it "tee" straight into that main pipe? So when you run into this blockage five feet along the pipe, it wouldn't be a sharp bend in the pipe that the manual cable can't go through?

  Have you determined that this is the exact place where the blockage exists that is causing the "glug"? When you took the trap apart, did you run water down the kitchen sink just to make sure the problem isn't between the sink and the trap? All you'd need to do is have a pail under the pipe and run some water down. If it runs freely, then you know the blockage is at the end of that 5.5 foot pipe.

  The reason I bring this up, the "glug" indicates that the water is going through, but slowly. There is a partial blockage. Very common in old pipes. After 50 years, a lot of soap scum/grease/food particle matter accumulates on the inside walls of the pipes, especially kitchen pipes. This crud generally builds up in the pipes just below the sink, moreso than further down. If the cable refuses to go through that last six inches, it may be due to a sharp bend in the pipe. If you had a solid blockage, the water would be backing up completely.

  First make sure the slow drain is not above the trap. If you are sure it's at the end of that 5.5 foot pipe, you may have to rent a small electric auger to get through that last 6 inches. Manual augers hang up easily at bends, and they have no power to ream crud out of a pipe. Sometimes they will poke a hole through a mass, and the hole closes up within minutes!

  Most rental places have small electric augers, even some Home Depots that have rental centers may have a few. Let me know what you find, OK? I like feedback about problems like this, it may help other questioners. Sharon