The lavatory sink is the likeliest clog in the house, says lifelong plumber Chuck White, vice president of technical and code services for the Plumbing-Heating-Cooling Contractors Association, a national trade group based in Falls Church, Va. And you can probably unclog it without bringing in a plumber, he says.

(That's unlike kitchen sinks, which are usually clogged by food bits -- as opposed to a tangle of hair -- and often tied into a disposal, making them a tough job for do-it-yourselfers.)

Degree of difficulty

Medium -- if it's the bathroom we're talking about. If, however, every drain in the house is backing up, this is over your head. Call a plumber. Kitchen sink clogged to a standstill? Most likely a job for a plumber.

Tools required

• Sink plunger (just like the toilet plunger, only shrunken to fit over the sink drain).

• Old rag.

• Drain snake (available at most hardware stores, but this moves you up into the advanced unclogging class).

• Plumber's phone number (just in case).

What to do

1. First, restrain from dumping any goo down the drain. And if you do and wind up calling the plumber, be honest about what you poured. Someone could get hurt; these products can contain noxious stuff that could burn skin and produce toxic fumes, especially if combined with other off-the-shelf potions.

2. Before you start pushing on the plunger, plug the overflow drain (that peephole in the actual sink, often just under the faucet) with the rag -- but don't let it slide into the hole. This closes the circuit and creates suction.

3. Time for the sink plunger -- it's about half the size of the toilet variety. Do not even think about using the toilet plunger. It's gross, and it's too big to form a tight seal around the sink drain.

4. If that doesn't work, try the drain snake, which is basically a hand crank and cable. You snake it down the drain opening, then turn the crank. It takes finesse. Apartment dwellers: If your sink and your neighbor's drain into the same pipe, you might snake through to the sink on the other side of the wall. Be careful.

5. Still not unclogged? Call the plumber.