Water damage rarely arrives the way people expect. While dramatic flooding makes the news, most of the calls we take across King County come from everyday household failures, a worn hose, a slow leak, a clogged gutter. Knowing the common causes is the first step to preventing them.

Plumbing Failures

Plumbing is the leading source of residential water damage. Pipes corrode, joints loosen, and supply lines fail, often without warning. A burst pipe can release hundreds of gallons in an hour, while a slow pinhole leak inside a wall can quietly soak framing for weeks before anyone notices. Older homes on the Eastside with aging galvanized or polybutylene plumbing are especially worth inspecting.

Appliance Leaks

Everyday appliances are connected to water lines, and those connections wear out. Common culprits include:

  • Washing machine hoses, rubber supply hoses crack and burst; braided steel hoses last far longer.
  • Dishwashers, failing seals and supply lines leak under cabinets where you can't see them.
  • Water heaters, tanks corrode and eventually fail, usually after 8 to 12 years.
  • Refrigerator ice makers, the small supply line behind the fridge is a frequent slow-leak source.

Roof and Exterior Issues

With roughly 37 inches of rain a year in the Puget Sound region, roofs and exteriors take a beating. Missing or aged shingles, failed flashing around chimneys and skylights, and clogged gutters all let water in. When gutters overflow, water can pool against the foundation and find its way into basements and crawl spaces.

💡 The Pacific Northwest factor

Our long, wet season means small exterior problems rarely stay small. A minor roof leak or a clogged downspout that might be harmless in a dry climate can cause real damage here simply because the rain keeps coming.

Basement and Crawl Space Water

Many King County homes have basements or crawl spaces that are vulnerable to groundwater. Heavy seasonal rain raises the water table, and water can seep through foundation cracks or back up through a failed sump pump. Poor exterior grading that slopes toward the house makes this worse.

Weather and Seasonal Events

While hard freezes are less common here than in colder states, the occasional cold snap can freeze and burst exposed or poorly insulated pipes, especially in crawl spaces and along exterior walls. Wind-driven rain and heavy storms can also force water past windows and siding.

How to Prevent the Most Common Causes

Most home water damage is preventable with routine attention:

  • Replace rubber washing machine hoses with braided steel and check appliance connections yearly.
  • Know where your main water shut-off is, and make sure everyone in the home does too.
  • Clean gutters at least twice a year, before and during the rainy season.
  • Inspect your roof and flashing annually.
  • Test your sump pump before winter and consider a battery backup.
  • Watch your water bill, an unexplained jump often signals a hidden leak.

No prevention is perfect, but understanding where water damage comes from lets you address the weak points before they fail.