Hair and soap scum work together to create clogging problems for your bathtub. The sticky soap scum makes bits of hair stick together to form a stringy clog that clings to the sides of the bathtub drain or gets caught on the metal parts. Here's a look at how to clean out a clogged-up bathtub drain.
Try To Pull Out The Hair Clog
Before you call a plumber to clean out the drain, try to dig out the hairball first. If your fingers are small enough, stick them in the drain and try to grasp the hair and pull it out. You can also bend a wire hanger or buy a drain-cleaning tool from the hardware store to fish out the hair clog. This might fix the problem, but if water is still slow to drain out and you can't feel any more hair in the drain, then there is probably a deeper clog.
Attempt To Use A Plunger
It isn't easy to use a plunger in a bathtub, so you may want to go ahead and call a plumber at this point. One reason it's difficult to use a plunger is because it's hard to get a good seal. You'll need to remove the overflow plate on the tub; otherwise every time you plunge, the air will escape out the overflow rather than go down the drain. Unscrew the plate and find a way to seal up the hole to block airflow. You can try stuffing a towel in the opening; just be sure there is no air leaking out when you use the plunger. After you've tried plunging the drain vigorously, test to see if water empties from the drain any more quickly. If it's still slow to empty, then the drain will probably need to be cleaned out by a plumber.
Snake The Drain
If you know how to use a drain snake, the next step is to snake out the bathtub drain. If you've never used one, it is probably best to call a plumber rather than waste money renting a snake and learning how to use it. The snake can be placed into the overflow opening in the tub or used in the plumbing cleanout outside. Your plumber might even suggest using a hydro jet rather than a snake depending on the nature of the clog. While hair clogs are common nuisances in bathtub drains, the problem might be due to tree roots in the sewer line. That's why it's usually best to call a plumber for drain cleaning services when you can't clear the clog by fishing out hair from the top of the drain.