A blocked or clogged drain is a pain, but it doesn't mean that you need to call a plumber. Most clogged drains can be easily cleared by using things that are around the house or just a few inexpensive tools.
All drains have a similar construction. At the bottom of the drainpipe is a curved section of pipe called a trap; under the sink, this trap is shaped like an "U." Most bathtubs have a slightly different shaped trap called a "P" trap, since it's shaped like the letter "P." The curves in the trap are there to "trap" some water in the drain line and prevent sewer gases from coming up the pipe and smelling up the house. Over time, however, the traps sometimes get blocked with things like cooking grease or food particles (in kitchen drains) or hair and soap scum (in tubs and bathroom sinks). Slow running drains are partially blocked, and drains that don't drain at all are obviously totally blocked.
Clearing Out a Blockage
The first step in unblocking a bathtub drain is to look at it and see if you can spot what's blocking it. In bathtubs, often a build up of hair and scuzzy soap scum will actually close up a drain. If you can see hair in the bottom of the drain, you can often just reach in and pull the clog out. Since that's not a lot of fun, you might want to try bending a wire coat hanger to hook onto the clog to pull it out. Alternatively, a pair of tweezers might work, or even a pair of needle nose pliers.
Using a Plunger
If you can't see the clog to pull it out, your next step is to try plunging the drain. A plumber's helper—plunger to some of us—didn't get its name without good reason, and it is one of the first tools a pro would use to clear a blocked drain. Put enough water in the bathtub or sink to cover the bottom of the plunger, block the overflow outlet with a rag, put the plunger over the drain, and push down and up five or six times. The pressure should clear any clog and open up the pipe. Lift up the plunger and the water should quickly drain away. If it doesn't, try plunging again—you might have just moved the blockage down the pipe where it got stuck again.
Note: On some bathtubs the drain stopper is attached to the overflow plate. In order to plunge the drain, you need to remove the overflow plate and the drain mechanism. The overflow plate is usually held in place by two screws, and after you remove them, you can gently remove the overflow plate and the drain mechanism at the same time.
Snaking a Drain
If a plunger won't clear a blockage, a "snake"—a long flexible steel cable wound on a handle—is the next level of escalation. In a sink you just feed the snake down the drain, but on a bathtub you need to feed the snake down through the overflow plate opening. Start by feeding about three feet of the snake into the opening, turning it as you push it forward. You will feel some resistance as you work the snake through the trap under the drain, and the turning helps to move the head through the trap. The snake should either break up the clog by pushing its way through it, or your turning will hook the end of the snake onto the clog and you can pull it out.
Once the snake is through the trap, move the cable back and forth through the drainpipe while still turning it. You may actually feel the clog when the snake hits it. Try running some water down the drain while moving the snake in the drain. If the clog is gone, the drain will run free. You may have to repeat this process a couple of times to get the drain cleared out, since some clogs are more persistent than others. Take care not to go too far when snaking a drain, otherwise you may run into complications with snagging the snake. If this happens, it may require professional help.
What About Chemicals?
Some people think using chemicals to clear a drain is an option. However, any chemicals that will dissolve a clog (usually grease-based) are highly caustic and damaging to the environment. No professional will ever use a chemical to clear a drain for exactly those reasons.
Keeping Drains Clear
Clearing a blocked drain isn't a lot of fun. It's much better to prevent a clog from happening in the first place. Here's some tips on how you can keep your bathtub drains free flowing:
- Don't just drop small pieces of soap down the drain assuming they will dissolve and wash away. This is how soap builds up in a drain.
- Use strainers in all your drains to stop hair from going down the drain. It's easier to clear out a strainer once a month than unblock a drain every six.
- Once a month, pour a kettle full of boiling water down the drain. This will melt any grease (body oil) and wash it away before it can build up. (Don't do this in a toilet; the boiling water could crack the porcelain).
- Every three months or so, pour a half cup of baking soda in the drain then slowly add a half cup of vinegar. Let the mixture sit in the drain for a few minutes and then rinse it away by running lots of hot water down the drain. This will not only keep your drains free running, but clean smelling as well.