Frozen Pipe Prevention for Colorado Winters

The single most common emergency call we get from December through February is a frozen pipe, and the most common pattern is the same every year: a cold snap drops the temperature below zero for forty-eight hours, the homeowner is at work or out of town, and a pipe in an exterior wall freezes, expands, and splits. The pipe holds while frozen. When the home warms back up and the ice melts, the split lets go and the homeowner walks back into a flooded kitchen.

The good news is that frozen pipes are almost entirely preventable, with a weekend of work that costs less than a single emergency visit.

Where pipes actually freeze

Pipes freeze in three places, in this order of frequency:

Exterior walls with insufficient insulation. Older Colorado homes (pre-1985 in particular) often have plumbing run inside exterior walls, with insulation that is either thin or has settled toward the bottom of the wall cavity. The pipe runs through cold air and freezes from the wall side first.

Crawl spaces with poor ventilation control. Crawls are vented to allow moisture to escape, but the same vents let cold air in during winter. A pipe running through an unconditioned crawl with open vents is a candidate.

Garages with hose-bib stub-outs. Many homes have a hose connection on the garage wall fed by a copper or PEX line that runs from the interior plumbing. If the garage is not heated, the line is exposed to outdoor temperatures even though the rest of the system is fine.

The kitchen sink supply lines are a fourth, less-common spot. Kitchen sinks on exterior walls with a single-pane window above are particularly prone.

What to actually do, in priority order

Insulate exposed pipes in unconditioned spaces. Hardware-store foam pipe insulation runs about $1.50 per foot. The job is one weekend afternoon. Wrap every length of supply pipe you can see in the basement, crawl space, garage, or attic. Pay particular attention to where pipes pass through exterior walls and where they connect to fixtures. A roll of insulation tape closes off the seams.

Drain and disconnect outdoor hose bibs every fall. Disconnect every garden hose, store them indoors, and either close the dedicated shut-off valve for the hose bib (most homes have one in the basement) or drain the bib through the freeze-resistant fitting. A hose left connected to a bib in winter is the most common single cause of a burst hose-bib supply line in this market.

Seal air leaks near plumbing. Cold air enters the home through gaps around pipes, vents, and rim joists in the basement. A can of expanding foam ($6 at any hardware store) and an hour of work seals most of them. Cold air that does not enter the home is cold air that does not freeze pipes.

Set the heat to at least 55 degrees if you travel. A Colorado homeowner who turns the heat off entirely while traveling for the holidays is the single highest-frequency emergency caller in this trade. Drop the thermostat to 55, not 40 or off. The savings on the gas bill are not worth the burst-pipe risk.

Open cabinet doors during a cold snap. When the forecast calls for sub-zero temperatures, open the cabinet doors under any sink that sits against an exterior wall (kitchen sinks, often). Warm room air circulating into the cabinet keeps the supply lines from freezing. The trick is small but it works.

Let one cold-water tap drip overnight on the worst nights. Moving water freezes meaningfully more slowly than still water. A pencil-lead-thin trickle on the cold side of one fixture during a night below zero is enough to keep water moving through the most vulnerable run.

If you think a pipe is already frozen

The signs: a faucet that runs only as a trickle, no water at one fixture while others work, frost on a visible run of pipe, or a refrigerator-water dispenser that has stopped producing.

What to do, in order:

1. Open the faucet at the affected fixture, both hot and cold sides. The opening relieves pressure as the ice melts and gives any water that is moving somewhere to go.
2. Locate the frozen section if you can. Visible frost on the pipe is the clearest indicator.
3. Apply gentle heat. A hair dryer set to medium, run from the faucet end of the run toward the wall, is the standard method. A heating pad wrapped around the pipe works too. Never use an open flame or a propane torch; the leading cause of pipe-related house fires in winter is a homeowner with a torch trying to thaw a frozen line.
4. If you cannot find or reach the frozen section, or if the line is in an exterior wall you cannot access, call us. We have the equipment to thaw inaccessible runs without damaging the pipe or the wall.

When to call us

If you have a pipe that has already burst and water is escaping into the home, shut off the main water valve at the meter immediately and call. We treat active flooding as a same-day emergency, day or night.

If you have a pipe you suspect is frozen but not burst, the call is still worth making. Thawing a frozen line is faster and cheaper than dealing with a burst one, and we can usually be on site within a few hours during business hours.

If you want a pre-winter walk-through of your home to identify and insulate the high-risk runs, the visit takes about an hour and costs less than a single emergency call. Most homeowners only think to do it once they have already had a freeze; we are happy to do it earlier.

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