How to Unclog a Bathroom Sink Drain

Drainage issues in a bathroom sink are almost always caused by a combination of hair, soap scum, and toothpaste residue collecting in the P-trap. When water starts to pool, the sink becomes a breeding ground for bacteria and odors, signaling that the pipe's internal diameter has been significantly reduced by this buildup. Successfully clearing the clog requires a methodical approach that avoids harsh chemical drain cleaners, which often damage metal pipes and fixtures. By physically removing the obstruction, you ensure a clear path for water and extend the life of your plumbing system without introducing corrosive materials into your home.

  1. Remove Hair From the Start. Unscrew or lift out the sink stopper assembly to inspect for hair clumps. Use needle-nose pliers to pull out any visible debris that has snagged on the crosshairs of the drain flange.
  2. Set Up for the Mess. Place a bucket directly underneath the P-trap to catch the water and sludge that will spill when you loosen the pipe joints. Lay down an old towel to protect your cabinet floor from any dripping residue.
  3. Disconnect the Trap Pipe. Grip the slip nuts on either side of the P-trap with tongue-and-groove pliers and turn them counter-clockwise. Once loose, unscrew the nuts by hand and slide the U-shaped pipe section away from the drain assembly.
  4. Scrub Every Surface. Dump the contents of the P-trap into the bucket and clear out the interior pipe walls with a stiff bottle brush. Rinse the pipe thoroughly in a separate sink or bathtub to remove all trapped hair and soap buildup.
  5. Reattach With Care. Slide the cleaned P-trap back into position, ensuring the slip washers are seated properly against the pipe ends. Hand-tighten the slip nuts firmly until they are snug; avoid over-tightening with pliers, which can crack plastic threads.
  6. Verify the Fix Works. Turn on the bathroom faucet to full pressure and run hot water for several minutes to flush the pipes. Check underneath the sink for any signs of moisture or dripping at the connections while the water is running.