Hair is a very common cause of bathroom drain clogs. You can slow down the accumulation of hair by using a screen over the drain to catch as much of the hair as possible. Another culprit is soap. Many soaps include grease and fat among their ingredients and over time, this can build up in your pipes. Dirt is another surprising contributor to clogged drains. The dirt you remove when you shower, wash your hands or your clothes goes down the drain and accumulates in your pipes. You can cut down on this accumulation by shaking off excess dirt before washing.