The customer called with a complaint of " My kitchen sink won't drain ".
The kitchen sink drain line was of two-inch diameter ABS pipe material, running in excess of thirty feet. For the length of the pipe, alone, it is not surprising he was having a clogged kitchen sink drain. When the run to the stack, or main sewer line is this long, the grade on the pipe is usually compromised. The International Plumbing Code requires the pitch of the pipe serving as the kitchen drain to fall 1/4" per foot of horizontal travel. The pipe runs in a ceiling which is usually made a distance of no more than 8" from the sub-floor above, due to the size of joist supporting the floor above the ceiling. The pipe may not penetrate the joist 2" from the top or 2" from the bottom of the joist.
Since the top of the two-inch pipe is set at no closer than two inches to the top of the floor joist, the bottom of a 2" pipe is resting at 4" from the top of the joist. So, plumbers attempt to have the last few feet of pipe running along side the joist to prevent being restricted by penetration of joists in the building code. This would mean the bottom of the 2" pipe can rest at bottom (or ceiling side) of the joist after running a distance of 16 feet. The 2" drain line running a distance of 30 feet was flat at some points and back pitched (pointing up in the direction of flow). A plumbing inspector should never had permitted the design of the plumbing system to have 2" pipe running more than 16 feet, according to The International Plumbing Code.
When a long length of pipe, carrying debris from the kitchen sink drain line has little fall, or is back pitched, the debris lays in the pipe until it accumulates and builds a blockage. The water attempting to flow down is not enough to remove the blockage because the debris, building over time hardens. Now, there is little the homeowner can do, but cable the line, attempting to perform his own drain cleaning. Chemical drain cleaners will not have an effect on the drain. The homeowner will need to use a drain cleaning service with a cable machine. However, a jetting or hydro-scrub is generally the best method to restore flow to this clogged kitchen drain line.
This particular customer's kitchen sink line was filled with egg shell and coffee. Apparently, the previous home owner had a bad habit of disposing of coffee grounds and egg shells in to the garbage disposer. Some people believe the egg shells will clean the disposer. Not sure why coffee grounds were flushed down the sink.
Since eggshells are calcium based, the shell fragments collected in the belly of the pipe adhere to grease that is washed down the drain over a period of years. This is a perfect recipe for a clog in the kitchen sink drain line. The grease and oils now have something to adhere to. Egg shells. Literally a mortar is being formed in the line. Layers of grease building in the line literally become like clay.
Sometimes a cable can be used to break up the blockage. However, do not be surprised if the kitchen sink backs up again. Grease is still stuck to the inside of the pipe. High pressure water jetting is a good option for cleaning the interior of the pipe wall. The ABS pipe spoken of in this man's kitchen sink line would function good as new. However, some investigative measures should be taken to correct the problem he had with pitch.
Click on this link to discover a tool that is made at varying sizes for all household size piping which may be useful to clear a kitchen sink drain.
Garbage disposals are also a culprit in a clogged kitchen sink. Click on this link to review step-by-step instruction on clearing a jammed garbage disposer.
Diagnosing and fixing the drainage problem for a sink, shower or bathtub may be a long and difficult process. Be safe. If fixing the issue is something that is risky or not being understood, contact a drain service company. The range of pricing for a company who cares to do the job correctly is within $145.00 - $225.00. This depends on material used in piping, age of the house which would help the plumber understand the plumbing code that was used in assembling the plumbing system, access to the plumbing and what is assumed to be creating the blockage.