A frozen pipe is most dangerous when it thaws, not while it is frozen. The ice expands and cracks the pipe, but the water does not escape until the ice melts and pressure returns. That means the moment to act is before you thaw it, with the main shutoff located and ready.
If a pipe in your home is frozen, shut off the water main first, then thaw slowly. If it has already burst and water is flowing, the main shutoff is the whole game.
If a frozen pipe has burst and water is in your home, call 303-816-0068. American Restoration answers 24/7 across Lakewood and the mountain communities.
What to do about a frozen pipe right now
Find the main shutoff before you do anything else, because a frozen pipe can become a flowing one the instant it thaws.
If the pipe is frozen but intact: locate the main shutoff and keep it within reach, open the faucet the pipe feeds so melting water and steam can escape, then apply gentle heat. A hair dryer, a space heater kept clear of anything flammable, or towels soaked in warm water all work. Start near the faucet and move toward the cold section so meltwater can drain.
Never use an open flame. A blowtorch or propane heater on a frozen pipe is a fire risk and can burst the pipe outright from thermal shock.
If the pipe has already burst: shut off the water main immediately, then the electricity to any area with standing water. Only then start removing water.
Why a frozen pipe bursts on thawing
The damage is done by expanding ice, but the flood waits for the thaw.
Water expands as it freezes. Inside a closed pipe, that expansion has nowhere to go, so pressure builds between the ice blockage and a closed faucet until the pipe wall splits. The split is often small and the pipe stays plugged with ice, so nothing leaks yet.
Then it thaws. The ice melts, pressure returns to the line, and water pours out through the crack. This is why a frozen pipe discovered in the morning can flood a house by afternoon, and why locating the shutoff comes before applying any heat.
Which pipes freeze
The pipes that freeze are the ones exposed to cold air, and in Colorado homes they are predictable.
Pipes in unheated spaces freeze first: crawl spaces, unheated basements, garages, attics, and exterior walls. Pipes on the north side of a house and those in walls with little insulation are the usual failures. An outdoor hose bib left connected to a hose in a freeze is a very common one, because the hose holds water against the valve.
A vacant or under-heated house is the highest risk. When the furnace is set low or fails while nobody is home, interior pipes that never freeze in normal use can freeze and burst, and the water runs unnoticed for hours or days.
How to prevent a frozen pipe
Keep heat on the pipes and water moving, and disconnect what holds water outside.
The EPA’s moisture guidance recommends insulating cold surfaces such as cold water pipes to prevent condensation, and the same insulation slows freezing (epa.gov/mold/brief-guide-mold-moisture-and-your-home). Foam pipe sleeves on exposed runs in crawl spaces, garages, and exterior walls are inexpensive and effective.
Before a hard freeze: disconnect and drain garden hoses, and shut off and drain the supply to exterior hose bibs where the valve allows. Open cabinet doors under sinks on exterior walls so household heat reaches the pipes. Let a faucet fed by a vulnerable pipe drip during an extreme cold snap, because moving water resists freezing and a dripping faucet relieves the pressure that actually bursts the pipe.
If you leave a Colorado home in winter: never set the heat below 55 degrees, shut off the main and drain the system for a longer absence, and have someone check the house during extended cold.
What a burst frozen pipe does to a house
A burst supply line can release a great deal of water quickly, and the damage compounds if it ran while nobody was home.
Water follows gravity and spreads along the path of least resistance, so a pipe that bursts on an upper floor damages everything below it. It saturates drywall, insulation, subfloor, and flooring, and it fills wall cavities that then hold water against framing.
Speed decides the outcome. The EPA states that drying wet materials within 24 to 48 hours will in most cases prevent mold growth, so a frozen pipe discovered and dried quickly is a very different loss from one that ran for two days. How fast mold growth starts covers that window, and detecting hidden water damage covers finding water that traveled inside walls.
Is a burst frozen pipe covered by insurance
Usually yes, as sudden and accidental water damage, with one important condition.
A burst frozen pipe is generally a covered water loss, because it is sudden and accidental rather than gradual. Whether homeowners insurance includes water and mold coverage covers how that works.
The condition is heat. Many policies exclude a frozen pipe burst if the home was unoccupied and the homeowner did not maintain heat or drain the system. Leaving a house cold in winter can convert a covered loss into a denied one, which is a strong reason to keep the furnace at 55 or higher and to drain the system before a long absence.
Document everything as with any claim, keep the failed section of pipe as evidence of a sudden burst, and photograph before removal begins. How a water damage claim works covers the process.
The bottom line
A frozen pipe floods when it thaws, so shut off the water main before applying heat and thaw slowly. Prevent it by insulating exposed pipes, disconnecting hoses, keeping cabinet doors open during cold snaps, and never letting a winter home drop below 55 degrees.
If a frozen pipe has burst in a home in Lakewood, Morrison, Evergreen, Conifer, Pine, Bailey, Kittredge, or Littleton, call 303-816-0068. Fast drying is the difference between a repair and a rebuild.
