Preventing Frozen Pipes During an Oregon Cold Snap

Most Portland winters are mild and wet. Then an east wind blows through the Columbia River Gorge, and temperatures fall into the teens or low 20s for days. Storms like the January 2024 ice storm show how fast this can happen. Homes built for mild weather often have pipes in crawl spaces, garages and outside walls, and those pipes can freeze overnight.

This guide focuses on the cold snap itself: what to do in the 48 hours before, during the freeze, and if a pipe freezes or bursts. For whole-season prep, see our guide to preventing frozen pipes in Portland's winter weather.

Why Cold Snaps Freeze Pipes in Portland Homes

When water freezes, it expands. In a pipe, the ice builds pressure between the frozen spot and the closed faucet. That pressure, not the ice itself, usually splits the pipe. The risk climbs when temperatures stay in the low 20s or below for several hours, especially with wind.

The pipes most at risk are in unheated crawl spaces, garages, attics and exterior walls. Hose bibs and pipes near foundation vents are also common trouble spots.

48 Hours Before the Freeze: Your Cold Snap Checklist

Forecasts usually give a day or two of warning. Use that time well.

• Disconnect garden hoses and put insulated covers on outdoor faucets
• Close foundation vents in the crawl space, then reopen them after the freeze
• Wrap exposed pipes in foam pipe sleeves, especially in the garage and crawl space
• Find your main water shutoff valve and make sure it turns
• Make sure your heat is working well, and call for heating repair now rather than mid-storm
• Plan for a power outage, since most furnaces need power to run

During the Cold Snap

Once the cold arrives, the goal is to keep warm air near your pipes and keep water moving.

• Keep the thermostat at 55°F or higher, even at night or when you are away
• Open cabinet doors under sinks on outside walls
• Let faucets on outside walls drip slowly, both hot and cold
• Keep the garage door closed
• Check faucets in the morning, when pipes are most likely to be frozen

Signs Your Pipes Are Frozen

• Little or no water comes out when you open a faucet
• Frost on a visible pipe
• A bulge or crack in a pipe
• Odd smells from a drain, a sign air is not moving

What to Do If a Pipe Freezes

Act fast, but do not take chances with heat or electricity.

1. Open the faucet the pipe feeds. As the ice melts, running water helps thaw the rest.
2. Warm the pipe gently with a hair dryer, heating pad or space heater. Start near the faucet and work toward the frozen section.
3. Never use a torch or open flame. It can start a fire or burst the pipe.
4. Keep warming until full pressure returns, then check the pipe for leaks.
5. If you cannot find or reach the frozen section, call a plumber.

What to Do If a Pipe Bursts

A burst pipe can release hundreds of gallons of water in a short time. Follow these steps right away:

1. Shut off the main water valve.
2. Turn off the water heater, so it does not run empty.
3. Open faucets to drain the remaining water.
4. If water is near outlets, cords or the panel, stay out of the area and turn off the power only if you can do so safely.
5. Move belongings out of the way and take photos for your insurance company.
6. Call for emergency plumbing.

When to Call for Emergency Plumbing in Portland

Some problems should not wait until morning. Call for emergency plumbing in Portland, OR if a pipe has burst, water is coming through a ceiling or wall, the whole house has no water, or you cannot find the frozen section. Sunset offers 24/7 live answering for plumbing emergencies.

For frozen pipe repair in Portland, OR, our licensed plumbers find the frozen or damaged section, thaw it safely and repair or replace the broken pipe. We use leak detection to find hidden damage inside walls and under floors. If your home has old pipes that keep failing, repiping may be the long-term fix. Damage to the main line from the street is handled by our water line repair team.

Sunset has served Portland homes since 1922. See our full range of plumbing services, or call 503-500-5866 any time a cold snap leaves you with frozen or burst pipes.

Frequently Asked Questions

At what temperature do pipes freeze?

Pipes in unheated spaces are at risk once outdoor temperatures stay in the low 20s or below for several hours. Wind and poor insulation raise the risk.

Should I let my faucets drip during a freeze?

Yes, for faucets on outside walls. A slow drip of hot and cold water keeps water moving and relieves pressure if ice forms.

How do I know if a frozen pipe cracked?

Once the pipe thaws, look for drips, wet drywall or puddles, and listen for running water when all faucets are off. A jump in your water meter reading with everything off also points to a leak.