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How to Avoid Clogging a Sink Drain

Learn why sink clogs occur and how to avoid them from Master Plumber John Wood in this plumbing repair video from Howcast.


Unfortunately like death and taxes, clogs are pretty much inevitable. Clogs occur for a number of reasons, long hair, greases and lipids in the line and then most commonly of the burbs is roots. Roots can be a real bug bear for the average homeowner and they can be extremely expensive to correct.

So I've made a kind of a basic illustration of a home, okay? To illustrate a point here. The sewer line coming out of this home running through the front yard should angle down and continue always at a constant pitch. Normally the standard pitch is a quarter of an inch per foot. Okay?

What happens a lot of times because of the way the earth above them and the enormous power to tree roots which is just incredible, I'll go into that in a second, you get a belly or what we call in the trade is sag in the line.

So yes, the water will still go out down the drain and run but instead of running and continuing down this way and out to the sewer we have a belly, this sag in the line and what happens is all of the waste just kind of sits there nasty, and it pools up.

So when that happens the plumber will take a snake and the snake is a big machine. It's a large, generally a two piece of affair and there's a half inch cable that comes off of it with a claw. Like a big metal blade, it's the same width of the pipe.

Let's say this is a six inch pipe, you have a big double six inch blade and the idea would be to cut through in a constant circular motion to cut through whatever's blocking here. Well the problem with a sag is you'll go right through and out into the sewer and then right back out but that junk will still be in the line.

It could be easily be 30 - 40 feet of it so in which case the sad news is that you need a backhoe. Okay? We're gonna dig up that line, remove the affected pipe and install it at the proper pitch so that the problem is rectified. That's 10, 15, $20,000 worth of work.

So let's eliminate the sag from the equation for a second and now we've got a properly installed, properly pitched sewer line. You see how I've drawn these hubs in here? This hub is where big 10 foot sections of pipe are being joined together.

Inside that hub normally speaking is lead poured in there. Sometimes it's in elastomeric seal of rubber in new installations but for this purpose we're gonna talk about an older house. Now what happens is over 100 years the big oak tree, that grandpop planted is now this big fearsome thing and these roots have just unbelievable sheer power to them.

What they do is they'll go searching for any source of water. Now with a 30 foot tall tree you might have root system the size of a Volkswagen. Okay? And when the root, a little tiny tentacle of a root the width of a pen get's inside this joint and finds that water in there, over two years it can grow to the width of a mans leg, bust the pipe out from the inside and cause all hell.

So the idea here is, especially when you know that you have a root penetration of the line, you maintain that line. Okay? You do so by accessing any number of clean outs that are code mandated. You have to have clean outs in the drainage system because clogs like death and taxes happen.

So you'll get a big clump of roots but normally speaking you'd have, this is a close up here of what the clean out would like, a four inch clean out. Let's say somewhere in the basement you have that four inch clean out right here. So that's a plug you can remove from the drainage system, bring in a heavy duty snake, a big machine.

This is best left for professionals or you could hurt yourself with the machine if you don't know what you're doing. You can run this line again, this double clawed fitting straight down the pipe and it's gonna run in and maybe at 20 or 30 feet it's gonna encounter the roots and then a fight is going to ensue.

It's gonna be chopping and ripping. It's very violent and you'll feel the snake kind of torque up and not move through in which case you pull back and you'll pull back and I guarantee a big, huge knot of roots.

Now to clear this line effectively a lazier drain cleaner will go in there, hit that knot of roots, cause the water to down and call it a day. Well, yeah, we've gotten this chunk of roots right here but what we don't know is that all the way down the line we've got root penetration. Okay?

So a good reaming of the pipe is absolutely necessary because not only do we have one joint, we have three of these hubs and we might even have a pipe with holes in it in which case the root is just strangling the pipe and a lot of times it's a hopeless situation and like I said in the beginning the roots have just crushed the pipe and have completely destroyed it.

Routine maintenance of the plumbing system is in everybody's best interest. Now another type of clean up that you might see in the house or in the home is an end clean out. This is what we call an end clean out versus a running clean out, running meaning it's in line with the pipe.

An end clean out, let me get rid of my little tree here, in an end clean out you would see on the edge of a Y. Right? A Y fitting being just like what it sounds, a Y, like this.

So this would be the end of a run, this could be a vertical drain coming down from upstairs into that Y and the waste will run out that way and you have this end clean out for specifically the purpose of being able to remove it and snake the line from the building out.

And that's how you clear a drain.

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