Topic: Unclogging Bathtub Drains

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 sinks this trap is shaped like an "U", while most bathtubs have a slightly different shaped trap called a "P" trap, since it's shaped like the letter "P".

http://www.doityourself.com/stry/unclogtubdrain