The first ten minutes
1. Shut off the water. Main valve if it is a supply line, the fixture valve if it is a toilet, sink or appliance. This is the only step that stops the damage growing, so it comes first even before looking at what happened.
2. Cut the power to the affected area at the breaker, if you can reach the panel without walking through water. If you cannot reach it safely, stay out of the space and call an electrician or the utility.
3. Open the lowest faucets in the house to drain remaining pressure out of the system, which stops the split continuing to release.
4. Photograph and video everything before you move anything. Wide shots of each room, close shots of the damage, the source if you can see it, and the water level on the walls. You cannot recreate this and your claim depends on it.
5. Call. A plumber for the pipe, a restoration contractor for the water. Move what you can carry to a dry room while you wait, and lift rugs off wet hardwood.
What not to do
Do not aim household box fans at soaked drywall. It dries the surface while the cavity behind stays wet, which is precisely how a drying job becomes a mold job.
Do not start tearing out drywall before the adjuster has documented the loss or the scope is agreed. Emergency mitigation to prevent further damage is expected; unauthorized demolition complicates claims.
Do not thaw a frozen pipe with an open flame, ever.
Why Colorado pipes break
It is not the absolute cold. Plenty of colder places break fewer pipes because they stay cold.
The problem here is the swing. Denver's overnight lows drop below freezing on roughly 150 nights a year, and the daytime high climbs back above it on most of them. Water expands about nine percent when it freezes, and inside a closed pipe that expansion has nowhere to go, so pressure builds between the ice plug and the closed tap until the weakest point in the line gives way.
The split usually happens during the freeze and stays sealed by the ice. The release happens on the thaw, hours later, often mid-morning while the house is empty. That lag is why so many of these are discovered as several inches of standing water rather than as a leak in progress.
Where they fail
Unheated crawlspaces. Attached garages. Exterior walls, particularly on the north side. Unheated basements in older homes. And outdoor hose bibs where a garden hose was left connected over winter, which traps water in the bib itself.
Older housing is disproportionately affected — the pre-1960 stock across Denver, Lakewood, Old Town Longmont and Fort Collins has the least protected plumbing runs.
Prevention, in order of value
Disconnect garden hoses before the first hard freeze and shut off the interior valve feeding each hose bib. Insulate supply lines in crawlspaces, garages and exterior walls. Keep the thermostat at 55°F or higher when you travel. Open cabinet doors under sinks on exterior walls so room air reaches the plumbing. In a sustained cold snap, run a pencil-thin trickle from the most exposed faucet.
Total cost: a few dollars and an afternoon. Typical burst pipe cleanup: $1,000 to $4,000 plus $150 to $2,000 for the plumbing repair.
Related: burst pipe cleanup, the Colorado cost guide, and Denver water damage restoration.
Frequently asked questions
Where is my main water shutoff?
In most Colorado homes it is in the basement or crawlspace on the wall facing the street, near where the supply enters. Some homes have it in a utility closet or at the meter pit outside. Find it now while nothing is wrong, and turn it to check that it actually moves — old gate valves seize.
A pipe is frozen but has not burst yet. What should I do?
Open the faucet that line feeds so melting water and pressure have somewhere to go, then warm the pipe gradually with a hair dryer or space heater, working from the faucet back toward the frozen section. Never use an open flame. If the frozen section is inside a wall or you cannot find it, shut the main and call a plumber.
Should I call the plumber or the restoration company?
Both, and it is fine to call them in either order. They do different jobs — the plumber repairs the pipe, the restoration contractor deals with the water in your building. Doing only the first leaves a wet structure, which is how a $2,000 job becomes a $10,000 one.
Is a burst pipe covered by insurance?
Sudden accidental pipe failure and the resulting water damage are typically covered by a standard homeowners policy. The pipe repair itself often is not. Claims can be contested if the carrier believes the property was left unheated, so keep the thermostat up when you travel in winter.