Quick Answer:
If your bathroom sink has been getting slower week by week, it’s usually a partial clog from hair, soap scum, or oils building up in the stopper, tailpiece, or P-trap. Start by removing the stopper and inspect for film, clear visible debris, then clean the trap. If those simple steps don’t fix it, call a plumber.
Why This Happens
- Hair combines with soap scum and body oils and sticks to the stopper and pipe walls.
- Heavy soaps and conditioners can leave a greasy film that slows water flow—this issue is common with some products like shampoos designed to rinse slowly. Slow drain after using heavy soap
- Small particles build up over time in the P-trap or the tailpiece where flow is slower.
- Recent plumbing work can leave debris in the line that reduces flow.
Step-by-Step What to Do
Step 1 — Slow inspection
- Run water to see how slow the drain is and whether it worsens when using more water.
- Check other fixtures: if the tub or toilet is slow too, the problem may be farther down the line.
Step 2 — Remove stopper and inspect for film
- Remove the pop-up or lift-and-turn stopper. Look for hair, gunk, and a greasy film around the stopper and the top of the drain.
- Clear out what you can by hand or with a disposable tool, then rinse the stopper and drain opening.
Step 3 — Plunge the sink
- Use a small sink plunger (cup plunger) with a little water in the basin to get a seal, and plunge several times.
- Cover the overflow opening with a wet cloth to improve suction.
Step 4 — Clean the P-trap
- Place a bucket under the P-trap, loosen the slip nuts, and remove the trap to clear trapped debris.
- Rinse the trap and inspect the tailpiece and trap arm for buildup before reassembling.
Step 5 — Use a drain snake for deeper clogs
- Feed a hand snake into the drain after the P-trap if the clog is further in; retrieve and remove debris slowly.
Step 6 — Finish and test
- Reassemble parts, run hot water to flush, and test with a normal flow. Repeat cleaning if needed.
- For minor residue, a short flush of hot water often helps. Avoid frequent chemical drain cleaners.
What Not to Do
- Do not ignore gradual slowdown. Small changes that are left usually become bigger clogs.
- Do not mix drain-cleaning chemicals or use them repeatedly; they can damage pipes and be hazardous.
- Do not force fittings or overtighten plastic slip nuts when reassembling; that can cause leaks or cracked parts.
When to Call a Professional
- If the sink stays slow after removing the stopper, cleaning the trap, and snaking the drain.
- When multiple fixtures are slow or there’s gurgling, which can indicate a blockage in the main line.
- If you notice leaks, damaged pipes, or if the problem started right after work was done on your plumbing — Slow drain after plumbing repair.
Safety Notes
- Turn off water and place a bucket under the P-trap before disconnecting it.
- Wear gloves to protect your hands from sharp debris and bacteria.
- If you must use a chemical cleaner, read the label, vent the room, and never mix products.
Common Homeowner Questions
- Why is the sink getting slower over weeks? Because hair, soap scum, and oils gradually stick to the stopper and pipe walls, narrowing the flow.
- Can I use store-bought drain cleaners? Occasional use of a mild product can help, but frequent or heavy chemical use can harm pipes and fixtures.
- Will a plumber need to replace pipes? Usually not for a gradual slowdown; most clogs are cleared by cleaning the trap or snaking. Replacement is rare unless pipes are damaged or corroded.