How To Find a Water Leak in Your House in Portland

Hidden water leaks usually don't show up all at once. You'll notice small things first, like a higher water bill or a soft spot in the floor. Most people miss these signs for months, and that's when the real damage starts.

We get calls every week from Portland homeowners who noticed something small and waited. By the time we open the wall, the drywall's soft and the studs are dark. Catching it early saves a lot of repair work.

Here's what to look for. You don't need any tools for this part. Just look around and pay attention to any smells.

One sign alone might be nothing. If you notice two or three together, it's worth checking.

Your water bill is the easiest clue to track. Pull up the last few months. Compare them to the same months last year. According to the EPA's WaterSense program, the average household's leaks can account for more than 9,300 gallons of water wasted every year. That water shows up on your bill, even if you never see a drop.

Portland's weather makes this harder. Our wet winters make it hard to tell a pipe leak from rain. A damp crawlspace in January might be groundwater, it might be a supply line. Many older homes in Sellwood, Laurelhurst, and St. Johns still have galvanized steel pipes. Those rust from the inside out. And they tend to leak slowly in places you can't see.

Here's a real one. A homeowner in Southeast Portland called us about a musty hall closet. She'd tried air fresheners and a dehumidifier. But the smell kept coming back. We traced it to a pinhole leak in a copper line behind the shower wall. It had been dripping for close to a year.

A musty smell is often the first sign of a hidden leak.

Floors can show signs of a leak too. Hardwood cups at the edges when water gets under it. Vinyl and laminate start to lift or feel spongy. Tile grout might darken and stay dark. Walk your floors in socks sometime. Cool or damp spots near a toilet or dishwasher are a red flag.

So what about sounds? Late at night the house goes quiet. That's the best time to listen. A faint hiss behind a wall, a trickle under the floor, or a toilet that refills on its own are all worth chasing down. And if you've caught the water meter ticking with everything shut off, you likely have a leak somewhere.

Don't wait to get that checked.

Most people don't realize slow leaks often do more damage than burst pipes. A burst pipe gets fixed that night. But a slow leak can run quietly for a year, soaking framing and feeding mold the whole time.

So the first step is figuring out which side the leak is on.

It changes who you call. It changes how much digging might happen. And it tells you if the water is going into your yard or into your house. Those are two very different problems.

You can narrow it down in about fifteen minutes. All you need is your main shutoff valve and a look at the meter. Here's how we walk customers through it over the phone:

One more case to know about. Is water bubbling up around the meter box itself or out at the street? That's usually the city's side. Call the Portland Water Bureau first so they can check their equipment.

House-side leaks are the ones most people picture. A running toilet. A drip under the sink. A slow leak behind a wall that stains the drywall. These are usually easier to find because you can see or hear them. But some hide well, like a pinhole leak in a crawlspace that nobody checks.

Service line leaks are harder to find. The pipe is buried, sometimes a few feet down, so you won't see a drop of water inside. Instead you get clues outside. A soggy patch of lawn that never dries out, even in August. Grass that's greener in one strip. A sinking spot in the yard or driveway. Low water pressure throughout the house.