Here in San Francisco, we live in character-filled homes. From Victorians to classic Edwardians, that charm comes with a trade-off: older plumbing. And those old pipes can sometimes spring sneaky, hidden leaks that go beyond our famous foggy dampness. Spotting them early is the key to preventing expensive, messy damage to your beautiful home.

First, know the signs. That persistent damp, earthy smell in a basement or crawlspace isn’t always just “old house smell.” Be suspicious of any unexplained stains on ceilings or walls, especially if they’re yellow or brownish. Peeling paint or bubbling wallpaper can signal moisture trapped inside. If you notice a section of your hardwood floor is warping or your tiles are becoming loose for no reason, water might be creeping in from below. Even a sudden, unexplained increase in your water bill is a major red flag from the city, telling you water is flowing somewhere it shouldn’t be.

So, what can you do? Start simple. Check under all your sinks for any moisture or corrosion. Look at your water heater and around your toilets for pooling water. Listen for the sound of running water when all your taps and appliances are definitely off. A good test is to read your water meter before bed and then check it first thing in the morning without using any water. If the number has changed, you’ve got a leak.

If you spot any of these warnings, don’t panic and don’t ignore it. For minor drips you can see from a supply line under a sink, you might temporarily tighten a connection. But for anything hidden in walls, ceilings, or floors, or if you just can’t find the source, that’s your cue to call a pro. At Starboy Plumbing, we use specialized tools like moisture meters and acoustic detectors to find leaks without tearing your walls apart unnecessarily. We find the exact problem, explain it clearly, and fix it right to protect the integrity of your San Francisco home. A small leak today can become a big headache tomorrow—catching it early is always the smartest move.