The lavatory sink is used almost every day, shaving, washing hands and face and brushing teeth. Needless to say, it has lots of opportunities to get clogged.

Typical residential lavatory sink drain lines are 1 1/2” in diameter and usually made of cast iron metal (in older homes) or ABS plastic (in newer homes). Many times the stoppage is from a collection of hair that gets trapped around the pop up drain assembly which simply requires the stopper to be removed and cleaned.

Lavatory sink Issue
Lavatory sink service at Complete Plumbing4u

Sometimes the lavatory sink drain stoppage is in the p-trap or drain pipe going into the wall. This will require special tools and knowledge to disassemble and clean.

Lavatory sink drain stoppage

Sometimes a lavatory drain stoppage can be cleared by using a plunger. Many lavatory sinks have an overflow drain built into the sink bowl itself. This overflow drain will have to be covered to prevent water from coming out while plunging.

Sink drain overflow
Lavatory sink faint sewer smell

The sink drain overflow can also be the source of a faint sewer smell in the lavatory sink as it is connected to the sewer line above the drain p-trap. The connection is usually via a trough built into the sink, if the water was to rise too high the overflow drain will route water into the drain line through the trough. Sometimes the trough gets waste residue that can cause odors.

Sink overflow odor

The easy way to remedy would be to mix baking soda and distilled vinegar, then using a funnel inserted into the overflow drain, pour the mixture into the overflow hole to clean and deodorize.

There are many preventative maintenance things a homeowner can do themselves:

(see blog page for more ideas)

  • Pouring a cup of bleach down the drain, let sit for 5 minutes then rinse. This will help to remove odors and help keep the drain clear.
  • Fill the bowl then pull the plug! When you run the faucet,water only drains in the bottom portion of the pipe, debris can start to accumulate along the top and sides of the pipe and before you know it your drain is stopped up and clogged. By filling the bowl and draining, water produces a swirling motion filling the piping and washing away debris and build up even on the top and sides of the pipe.
  • Run hot water for a few minutes after using the sink. This will help dissolve and rinse away debris.


Complete Plumbing Heating and Air has everything needed to tackle even the toughest problems with lavatory sink drain lines. We have high pressure water jetters, sewer pipe bursting, sewer liners, cameras, sewer locators (click to appropriate pages).