what clogs the drain?

Hello, was wondering if anyone could suggest what this greyish and soft matter was that was clogging our washer/kitchen sink drain:



The 6 feet horizontal pipe, which is in the crawl space and is right downstream from the the kitchen sink, was tightly stuffed with this matter. The pipe is 2" ABS. There is also a washer 8 feet upstream from the kitchen sink. But the clog started right after the sink.

What is this stuff? If this is organic waste from the sink, why doesn't it get digested/broken down by the bacteria? Or is this some inorganic stuff that has been collecting down there over the last two-three years (I remember washing drywall knives in the sink couple of times)?

Would appreciate any comment. Thanks and best wishes, h.

 

Washing dry wall knives could certainly cause the problem. Soak them in a bucket of hot water.

 

Looks like grease to me... Its often what I pull out after snaking kitchen lines....

 

I second Lawrosa. It's grease.

I see it frequently with some of my rental houses. Some can clog a pipe in a year while others will never have a problem. What you eat and how you cook and clean has an effect.

Bacteria can break down or digest grease but it's a very, very slow process. It's such a slow process that it's one of the major killers of septic systems. What you see in your pipes is easy to remove. When it makes it's way out into a leach field it can be a major expense.

 

Thanks for all the responses! Yes, this could be grease. We mostly scrape stuff like butter or grease that hardens at room temp off the kitchenware before washing it. I guess still a lot makes it down the drain. h.