Plumbing drainage problem

[Pleonast]

My kitchen sink has a drainage problem. After running the water tap full stream for about a minute, the water starts rising out of the drain. It slowly drains offs.

We've checked the trap under the sink--it's clear. It's not a problem with the house's main sewer line to the street; that was recently replaced. We ran a powered snake into pipe and that helped speed up the drainage some. Is there anything else we should be doing? Do we just need to run the snake more and hope to eventually clear a blockage?

We're generally not DIYers, but trying to learn. Please use simple explanations. (Not sure if this forum or GQ is more appropriate, so feel free to move it about.)

[raindog]

Originally Posted by Pleonast

My kitchen sink has a drainage problem. After running the water tap full stream for about a minute, the water starts rising out of the drain. It slowly drains offs.

We've checked the trap under the sink--it's clear. It's not a problem with the house's main sewer line to the street; that was recently replaced. We ran a powered snake into pipe and that helped speed up the drainage some. Is there anything else we should be doing? Do we just need to run the snake more and hope to eventually clear a blockage?

We're generally not DIYers, but trying to learn. Please use simple explanations. (Not sure if this forum or GQ is more appropriate, so feel free to move it about.)

If other drains in the house are clearly normally, then you can assume it's a local blockage; local meaning it's in the sink drain itself between the trap and the main drain line. (Assuming it's not in the strainer.....)

What is the drain made of? Galvanized? PVC?

My swag is it's in the sink drain, after the trap but before the main drain. You sink drain is probably 1 1/4", and the main drain 3". If you're sure the other drains are draining correctly, I'd re-snake the sink drain.

[Pleonast]

All the pipes that we can see from above are PVC. The crawlspace under the house is tight so we haven't checked things from below.

There's a bathroom directly above the kitchen that we infrequently use. Is there a chance that its drainage could be affected as well? I'm assuming that by the time its drainage combines with the kitchen's that the pipe is big enough to be unlikely to be clogged.

Thanks for the response. We can do the snake again as needed (except that it means disrupting my kitchen ), but I wanted to get some reassurance that there wasn't anything critical we're missing.

[Booker57]

Drains can be clear, how are the vents stacks? If the water is going out but air is not coming in fast enough it will act like a slow drain.

[Pleonast]

Originally Posted by Booker57

Drains can be clear, how are the vents stacks? If the water is going out but air is not coming in fast enough it will act like a slow drain.

Oh, tell me more! I have no idea what those are.

[Booker57]

Not to be mean but I am not a good enough comunicater to expalin this, Google plumbing, or get a good DIY book.

[Dreamy B]

The vent stack serves to vent the air in the pipes that's trapped by the water going down the pipe. For example, if you turn a full bottle of soda upside down the soda will glug out slowly. However if you were to poke a whole in the bottom of the soda and turn it upside down, the soda would flow out smoothly and much quicker. Same thing with your sink. A pipe connects the drain that extends up thru the roof to let the displaced air out of the system.

Ever 'shotgun' a beer?

Anyway, it's not impossible that your vent is clogged but it's a little rare. Sometimes birds nest in them and sometimes they just get clogged. I'd guess that your sink is slow because it's still clogged and the snake didn't reach the clog or the snake was too small for the pipe. I'd recommend giving liquid plumber a shot. For 3 or 4 bucks and 15 minutes of work, it can be effective. I've had good luck with this on slow drains.

[Pleonast]

We've considered Liquid Plumber, but it would take a lot. Since the clog isn't in the trap, to get the LP to the clog, we'll have to put in enough overflow the trap so some gets to the clog in the drain pipe. I guess it's worth a shot, although I hate the stuff.

[Pleonast]

In case anyone cares to hear the happy ending, we filled the sink with water and poured in 160 ozs of Drano Gel. It took about 5 hours, but the clog was busted. Yay!

[gotpasswords]

Good to hear that your sink is draining nicely now.

I was going to come in here to recommend NOT using caustic or lye-based drain cleaners in a kitchen sink, as the inevitable grease build-up in the pipes mixed with lye will form an amazingly hard soap that's almost completely waterproof. Said soap needs to be mechanically scraped out of the pipes, or it's often a whole lot faster to just replace the pipes.

The better choices for kitchn sinks are:

Running your hottest possible water full-force for 15-20 minutes or until the drain clears (or until the sink fills up!)
Snaking the drain
Using an acid-based drain cleaner.

Please note that drain cleaners are only effective on what's submerged in them - so they're good for gunk in the trap, but not so good for stuff on the sides of pipes if there's any flow. At best, you'll moisten the clog while the cleaner flows away, and you might soften the outer layer of the clog. The newer "foaming" cleaners are intended to keep drain cleaner on the clog for a longer time, so they're hoped to be more effective than the non-foaming types.

Drain cleaning chemicals are also dangerous - be sure to tell a plumber what you've used if you have to call someone, and be sure to flush it all away before trying a different type. Caustic and acid-based cleaners can become explosive if mixed together.

[Sparky812]

Originally Posted by Pleonast

In case anyone cares to hear the happy ending, we filled the sink with water and poured in 160 ozs of Drano Gel. It took about 5 hours, but the clog was busted. Yay!

I hope this was a typo, but 160 ounces? Please tell me you didn't put 160 ounces of Drano gel down your kitchen sink!?

[NDCompuGeek]

Originally Posted by gotpasswords

Drain cleaning chemicals are also dangerous - be sure to tell a plumber what you've used if you have to call someone, and be sure to flush it all away before trying a different type. Caustic and acid-based cleaners can become explosive if mixed together.

Ummm, just HOW explosive , and what examples of caustic and acid are available to the general public? Is this something I should be extremely concerned about? Something about my pipes EXPLODING as I'm trying to clear a clog really concerns me....

[Sparky812]

Originally Posted by NDCompuGeek

Ummm, just HOW explosive , and what examples of caustic and acid are available to the general public? Is this something I should be extremely concerned about? Something about my pipes EXPLODING as I'm trying to clear a clog really concerns me....

While it is possible, I'd be more worried about the zombie apocalyse.

[TruCelt]

My Grandfather had a kitchen drain that slowed down every six months or so. As soon as the slowing became noticable (don't do this to a seriously clogged drain!) he would pull out the biggest lobster pot in the house, fill it with water and cheap rock salt, then boil it and send the whole pot down the drain all at once.

He said the water gets hotter than boiling plain water, and the salt mixes with the buildup as it loosens and keeps the pieces from bunging up together into an even worse clog further down the pipe.

He was foreman of the pipefitting team that built the USA's first nuclear submarine, so when it comes to pipes I generally follow his advice. LOL!