Water under a sink usually comes from a leaking drain pipe, loose connection, or failing water supply line. In many Winston-Salem homes, older shut-off valves and worn plumbing parts are common causes too. The good news is that most sink leaks are small at first and can often be fixed before major damage happens.

What usually causes it

Leaking drain pipe: The curved pipe under the sink is called the P-trap. It holds water to block sewer gas from coming back into the house. Over time, the connections can loosen or the pipe can crack and start dripping.

Bad supply line: The small water lines that connect to the faucet wear out over time. Many leaks start from the fittings near the shut-off valves under the sink.

Loose sink drain: The drain connection right at the base of the sink can decay over time. Water may only leak when the sink is draining.

Old shut-off valves: Many older homes around Ardmore, West End, and downtown Winston still have original shut-off valves under the sink. These valves can drip around the handle or connection points after years of use.

What you can try first

Dry everything completely first. Then run the faucet and watch closely to see where the water starts.

If the leak is coming from a connection, you may be able to tighten it slightly with a wrench. Do not force plastic fittings too hard or they can crack.

If the leak is coming from the P-trap, check to make sure the connections are lined up correctly. Many small sink leaks happen after someone stores items under the sink and bumps the pipe loose.

If water is spraying from a supply line or shut-off valve, turn the water off right away. You can read our guide on where to find your main water shut-off valve if you are not sure where it is.

When to call a plumber

Call a plumber if the leak will not stop, the cabinet is swelling, the shut-off valve will not turn, or the pipes are badly corroded. Water damage under sinks gets expensive fast, especially in older homes with particle board cabinets and wood floors.

You should also call if the leak keeps coming back after tightening connections. At that point, something is worn out and needs to be replaced.

What this costs

Sink leak repairs usually start around $290 depending on what is leaking and how much needs to be replaced. Shut-off valves, supply lines, and drain repairs are usually straightforward if caught early.

We see a lot of sink leaks in older Winston neighborhoods where the original shut-off valves and drain parts are reaching the end of their life. Catching a small drip early is much cheaper than replacing cabinets or flooring later.

If you need help finding or fixing a sink leak, our Winston plumbing team can take a look and explain your options.