A wet cabinet floor under the bathroom sink is easy to miss until the wood swells or the smell starts. Most of these leaks are small and simple, but some come from the pipe in the wall, which needs a pro. This guide covers the 7 most common causes of a leak under the bathroom sink in Murrieta homes and how to find yours. If you need help, call (951) 299-3473, 24/7.
We are the local team for leak detection Murrieta CA homeowners call when the source isn't obvious.
What causes a leak under the bathroom sink?
The most common causes are a loose or worn supply line, a leaking shut-off valve, a loose P-trap nut, a failed drain gasket, a faucet base leak, an overflow leak, and a pipe leak inside the wall. The first five are usually quick fixes. A leak in the wall needs testing to find.
- Supply lines. The flexible hoses from the valves to the faucet can crack or loosen.
- Shut-off valves. Old angle stops often drip at the stem, especially after you turn them.
- P-trap. The curved drain pipe has slip nuts that loosen over time.
- Drain gasket. The seal where the drain meets the sink bowl can dry out and leak when water drains.
- Faucet base. Water can seep past the faucet and drip down into the cabinet.
- Overflow. Many bathroom sinks have an overflow hole; a bad seal leaks when the bowl is full.
- Pipe in the wall. A pinhole or loose fitting behind the vanity leaks all the time, even with the sink off.
