Weird kitchen sink blockage--snake not fixing it

[canadave]

Just an amateur homeowner here....I'm stumped trying to clear a kitchen sink blockage, hoping you all might be able to offer a suggestion.

Recently we noticed the kitchen sink in our residence (a bungalow) was starting to drain more slowly than usual. Oh well, no big deal, we'll get to it and clean it at some point. A little while later we bought some Drano and poured it down. No effect. We tried it twice more over the next couple of days. Still no effect. And the blockage got worse and worse over the next few days.

OK, hmmm. I grabbed myself a 25-foot plumber's snake and figured I'd just clear the blockage. To my surprise, although I fed the snake out all the way, it didn't find any blockage, nor did it come back up with anything snagged in the nose end of it.

At a loss, I decided to try to calculate approximately where the blockage might be. I waited a day or two for all the water to drain completely (it was draining, just slowly), then measured out a bunch of water and poured it down. Using the volume of a cylinder formula, I was able to calculate that the blockage (to my surprise) was only about 10 feet along the pipe from the base of the sink.

We've barely been using the sink since then--just very minimally. And now today the sink is completely blocked--water isn't going down at all anymore. I tried snaking it four more times--again, I can extend the snake all the way, but it's not encountering anything.

So now I'm stumped. Any ideas before I call in a plumber?

 

[Helper Dave]

Did you snake up the vent instead of down the drain? REAL easy to do. Try snaking it, and having someone in the basement/crawlspace to make sure the cable made its way down towards the clog.

 

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[Reach4]

Got a basement under that kitchen?

Clogs often happen where the flow turns from vertical to horizontal.

 

[canadave]

Did you snake up the vent instead of down the drain? REAL easy to do. Try snaking it, and having someone in the basement/crawlspace to make sure the cable made its way down towards the clog.

We were wondering if that might be the case. If so, how can I avoid doing that?

 

[canadave]

Got a basement under that kitchen?

Clogs often happen where the flow turns from vertical to horizontal.

Yep--the lower part of the bungalow is under the kitchen. And I would bet that that change to horizontal is just about at 10 feet, which is just about where the clog is.

 

[Reach4]

We were wondering if that might be the case. If so, how can I avoid doing that?

If you have a vent right above there, you can snake down from the roof.

If you have a trap adapter at the wall, you can see which way the snake is going.

I had a kitchen above the basement, and the drain pipe was exposed. I cut out maybe a 10 inch section of pipe. I pushed a medium Brasscraft drain bladder down the open pipe, and turned on the water. Cleared it. Then put that same segment of pipe back in place with flexible couplings.

Did the drain bladder thing again a few years later.

If your space is more finished, you could add in a wye as a cleanout under the sink or on the lower floor.

 

[canadave]

Thanks....problem is, other than the parts of the drain pipe in the under-sink area, it's pretty difficult to access any parts of the drain pipe system until near the very end where it goes down to the sewer. we have a drop ceiling that makes it pretty difficult to access the pipe.