Keeping pipes from freezing in a Colorado winter

Northern states get cold and stay cold. Colorado oscillates, sometimes forty degrees inside a single day, and that pattern is harder on plumbing than constant winter. Water in a vulnerable pipe gets repeated cycles of freezing, expanding, thawing and refreezing, working at a joint or a weak section until it gives.

October: the checklist that prevents most of it

Almost every burst pipe we attend in Arvada traces back to something that could have been done in twenty minutes in autumn.

• Disconnect every garden hose. This is the single highest-value item on the list. A connected hose traps water against the bib; the freeze travels back along the pipe into the rim joist, and the split often does not reveal itself until spring, when someone opens the outside tap and water pours into the basement.
• Shut off and drain outdoor lines at their interior valve where one exists.
• Blow out the sprinkler system before the first hard freeze, not after it.
• Insulate exposed pipe in crawlspaces, garages, and along exterior walls. Foam sleeves cost very little and go on in minutes.
• Seal drafts where cold air reaches pipe — rim joist penetrations, crawlspace vents, the gap where a line comes through into the garage.
• Confirm your main shut-off turns. Do it now, while nothing is wrong.

Which pipes actually freeze

Not all of them, and not randomly. The casualties are consistently:

Pipes in exterior walls, especially on the north and west sides — no afternoon sun, and the prevailing wind. Pipes in unheated crawlspaces and garages. Anything feeding a hose bib. Lines running out to a detached garage, workshop or remote outdoor tap, which are typically the oldest and least protected plumbing on a property. And in older homes, runs installed before anyone thought carefully about where insulation should sit relative to pipe.

Wind matters more than people expect. A still fifteen-degree night is meaningfully less dangerous than a windy twenty-degree one, because moving air strips heat from a wall cavity far faster.

On a genuinely cold night

• Open the cabinet doors under sinks on exterior walls so household heat reaches the pipes.
• Let a vulnerable faucet drip — moving water is far harder to freeze, and the open tap relieves the pressure that actually splits pipe.
• Keep the thermostat steady rather than setting it well back overnight.
• Keep the garage door shut if there is plumbing in there.
• If you are travelling, do not set the heat below the mid-fifties, and have somebody check the house.

If a pipe is already frozen but has not burst

You will know because a tap gives nothing, or a trickle, while others run normally. Act quickly — the pipe has not failed yet and you may be able to prevent it.

Open the affected tap so there is somewhere for water and pressure to go as the ice releases. Warm the pipe from the tap end backwards toward the frozen section, using a hair dryer, a heat lamp, or towels soaked in hot water. Never use a blowtorch or any open flame: you will damage the pipe, and every year somebody sets a wall cavity alight doing exactly this.

If you cannot reach the frozen section, or the tap stays dry after warming, shut the water off at the main and call. A pipe that has split while frozen will announce itself the moment the ice melts, and it is much better to be standing there when it does.

Spring: check what winter did

The first time you use an outdoor tap in spring, have somebody watch inside — in the basement or crawlspace near where that line runs — while you open it. A hose bib that split during winter often gives no sign at all until it is pressurised again, and the water goes into the structure rather than out of the spout. Ten seconds of looking saves a great deal.

Written by the team at Arvada Plumbing Co., 5760 Marshall St, Arvada, CO. Got a question this did not answer? Call (720) 743-3832 — we would rather answer it than have you guess.