Leak under the sink in Manhattan: find it, stop it, get it fixed
In a Manhattan apartment a small leak is never just your problem. Water travels to the unit below fast. Here's how to find where it's coming from and keep the damage small.
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Emergency? Gas smell, CO alarm, fire, sparking or flooding: get to safety and call 911 first.
Stop the water first
- Clear out the cabinet and put down a towel and a bowl.
- Close the two small shutoff valves under the sink (turn clockwise). If they're stuck or leak themselves, don't force them.
- If water won't stop, tell your super or building management right away. Many apartments don't have their own main shutoff.
Find where it's coming from
Dry everything, then run water and watch with a flashlight:
- Supply lines (hoses from the valves to the faucet): drips at the connections, or old rubber lines that are bulging.
- Faucet base: water splashing or seeping through worn seals and running down.
- Drain and P-trap: drips at slip nuts only when water is draining.
- Dishwasher or garbage disposal connections, if you have them.
- Sink rim or strainer: failed sealant around the basket.
- If the cabinet is wet but none of these drip, the water may be coming from upstairs or from the wall. Tell the building.
What you can safely do
Hand-tightening a loose P-trap slip nut is fine. So is swapping a supply line on fixtures you're comfortable with, with the valves closed. Anything involving the shutoff valves, pipes in the wall, or building risers should go to a licensed plumber.
What a plumber typically does
Replaces supply lines or stuck shutoff valves, resets or replaces the trap, re-seals the strainer, or repairs or replaces the faucet. In NYC, plumbing beyond small repairs must be done by or under a DOB Licensed Master Plumber. The cost depends on parts and access, so ask for a quote.
Manhattan co-ops and condos
Most buildings require any contractor to send a certificate of insurance (COI) naming the building and managing agent before they're allowed up. Many also limit work to weekday hours. Ask management for their COI requirements up front so the plumber isn't turned away at the lobby.
Questions
Is a slow drip under the sink urgent?
Fix it soon. Slow leaks rot cabinets, grow mold and can damage the apartment below. Put a container under it and shut off the valves until it's repaired.
Who pays if my leak damages the unit below?
That depends on your lease, your bylaws and your insurance. Tell your building and your insurer quickly and take photos.
Will the plumber need a COI for my building?
Almost always in Manhattan co-ops and condos. We match you with pros who keep insurance on file, so they can usually send one quickly.
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