A small leak under the kitchen sink is easy to miss until the cabinet base starts swelling or smelling musty. By then, the water has often been dripping for weeks. Finding the source early saves you a cabinet replacement.
Step 1: Find where the water is coming from
Empty the cabinet, dry everything with a towel, then check each part one at a time:
- Run the tap without filling the sink. Check the water supply hoses and the tap base.
- Fill the sink, then let it drain. Watch the strainer and the waste pipe.
- Wrap a dry tissue around each joint. A wet tissue shows you the exact spot.
The most common causes
Loose pipe joints
The nuts on the waste pipe and trap loosen over time from vibration and hot water. This is often the easiest fix.
Worn washers and seals
Rubber washers inside the joints harden and crack with age, so even a tight nut can still drip.
Failed sink strainer seal
The seal between the sink basin and the drain strainer breaks down. Water leaks when the sink drains, not when the tap runs.
Leaking flexible hoses
The braided hoses that connect your mixer tap to the water supply wear out. A bulging or rusty hose should be replaced right away, before it bursts.
Corroded stop valve
The small valve on the supply pipe can corrode and weep, especially in older homes.
What to do right now
- Put a bucket or tray under the leak
- If the leak is from the supply side, close the stop valve under the sink
- Keep the cabinet dry and open so it can air out
Tightening a loose joint by hand is fine. But if a washer, seal, hose or valve has failed, the part needs replacing, and over-tightening can crack plastic fittings.
When to call a plumber
- The leak continues after you’ve tightened the joints
- The flexible hose is bulging, rusty or more than a few years old
- Water is coming from the wall or the cabinet floor, not from a visible joint
- The cabinet base is already swollen or soft
Fix it before it damages your cabinet
Handyman Service Hero repairs sink leaks, replaces flexible hoses, traps, strainers and stop valves, and installs new kitchen taps in HDB, condo and landed homes across Singapore. Call or WhatsApp us a photo of the area under your sink, and we’ll tell you what’s needed with a clear quote upfront.
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