Most winters in Clark County and the Portland metro stay mild enough that pipe insulation feels optional. Then, usually once or twice a season, a cold snap settles in for several days of sustained sub-freezing temperatures — and homes built for a mild marine climate, with pipes routed through garages, crawl spaces, and exterior walls that were never designed for hard freezes, start failing. Prevention here isn’t complicated, but it does need to happen before the cold arrives, not during it.
Why this climate is particularly exposed
Homes in colder inland climates are typically built with supply lines run through conditioned interior space specifically because hard freezes are routine there. Pacific Northwest construction, especially in older homes, often routes pipes through unheated garages, exterior walls, and vented crawl spaces — reasonable in a climate where temperatures rarely drop below freezing for more than a day, but a real liability during the multi-day cold snaps that show up most winters. Older homes with galvanized or thin-walled copper supply lines are more vulnerable than newer construction, but any exposed line in an unheated space can freeze given enough sustained cold.
What to do before the cold arrives
Insulate exposed pipe runs. Foam pipe insulation sleeves are inexpensive and take an afternoon to install on the lines that matter most — anything running through a garage, crawl space, or exterior wall. This is the single highest-value prevention step, and it’s far cheaper than a burst-pipe restoration.
Find your water main shutoff now, not during an emergency. In most Clark County and Portland-area homes, it’s in the crawl space, the garage, or a covered box near the street. Make sure more than one person in the household knows where it is and how to operate it. The gap between shutting off water in five minutes versus thirty minutes is often the difference between a contained drip and a multi-room flood.
Disconnect garden hoses before the first hard freeze. A hose left attached to an exterior spigot holds water in the line back toward the house, and that trapped water is what freezes and splits the pipe just inside the wall — not the spigot itself.
Seal obvious drafts near pipe runs. Gaps around foundation vents, crawl space access doors, and garage doors let cold air reach pipes that would otherwise stay a few degrees warmer than outside air. Weatherstripping and vent covers are a small job with real effect.
Know your crawl space vent situation. Many older Clark County homes have foundation vents that are meant to stay open most of the year for moisture control, but some newer code allows or requires closing them during hard freezes. If your crawl space vents are the manually operated type, closing them during a forecasted multi-day freeze reduces cold air reaching your under-house plumbing.
What to do during an active cold snap
Let a faucet drip on exterior-wall plumbing. A slow, steady drip keeps water moving through the line, and moving water is much more resistant to freezing than standing water. This matters most for any fixture on an exterior wall or fed by a line that runs through an unheated space.
Open cabinet doors under sinks on exterior walls. This lets warmer interior air reach the supply lines under the sink instead of leaving them sealed off in a cold, enclosed cabinet.
Keep the thermostat consistent, including overnight. Turning the heat down significantly at night to save on the bill is reasonable most of the year, but during a forecasted hard freeze, keeping the interior temperature steady protects pipes routed through interior walls near exterior surfaces.
If you’re leaving town during a cold snap, don’t turn the heat off. Set it no lower than around 55°F, and consider asking a neighbor to check the house, or shutting off the water main entirely if you’ll be away for an extended stretch and won’t be able to respond to a problem. Insulating pipes and knowing the shutoff are also the top two items on our broader winter storm prep checklist, worth reviewing before the season’s first serious cold front.
If a pipe freezes anyway
A frozen pipe that hasn’t burst yet can sometimes be thawed safely — but a pipe that’s already split needs the water shut off immediately, not a thawing attempt. If you find a frozen section (a faucet that won’t run, a section of visible pipe with frost on it) and there’s no sign of a split, you can try gently warming it with a hair dryer on low heat, moving continuously and never using an open flame. If you can’t tell whether it’s split, or water starts appearing anywhere near the frozen section, shut off the main and call. For more on what a burst pipe actually costs to repair and restore, see our guide on what a burst pipe costs to fix.
When to call
If a pipe has already burst, shut off the water main first, then call. We dispatch burst pipe repair crews to extract water, find hidden moisture with thermal imaging, dry the structure to IICRC standards, and rebuild what didn’t survive — one company from the first call through the finished repair. Sudden pipe bursts from freezing are typically covered by standard homeowner’s insurance, and we bill your carrier direct so you pay only your deductible.