Water — Track 1: Protect
Pipes, stored barrels, well pumps, rain barrels, and outdoor fixtures all respond differently to freezing. Here is what to protect, how to protect it, and what to do when something freezes anyway.
The mechanics
Water is one of very few substances that expands when it freezes. The expansion is about 9%, which does not sound like much until you consider that it is happening inside a rigid pipe or sealed container with no room to give. The ice itself rarely causes the break. What happens is that ice forms in a section of pipe and creates a plug. Water trapped between the plug and a closed faucet has nowhere to go. As more ice forms, the pressure between the plug and the faucet builds until the pipe fails at its weakest point.
This is why burst pipes often break in a spot that is not frozen at all. The failure occurs where the pressure is highest, which may be feet or even a full floor away from the ice blockage. It is also why a dripping faucet helps: the open faucet gives the pressure a place to escape instead of building against the pipe wall.
The same physics apply to stored water containers, rain barrels, well pump heads, and any other enclosed vessel holding water. The solutions differ by system, but the underlying problem is always the same: water needs room to expand, and pressure needs a place to go.
Indoor plumbing
Most pipe failures happen in unheated spaces inside the building envelope: crawl spaces, attics, garages, and along exterior walls. These areas lose heat fastest during cold snaps and are often the last places homeowners think to check.
Foam pipe insulation sleeves are the most cost-effective first line of defense. They fit over pipes of standard diameters (1/2", 3/4", 1"), cost under a dollar per linear foot, and install in minutes with no tools beyond a utility knife. Slit the sleeve along the seam, press it over the pipe, and seal the seam with tape or the adhesive strip if the sleeve includes one.
Focus on pipes in crawl spaces, unheated basements, attics, garages, and along exterior walls. Any pipe that runs through an unheated space or through an area exposed to drafts is a candidate. If a pipe has frozen in a previous winter, it is a priority.
For pipes that insulation alone cannot protect, particularly pipes in uninsulated exterior walls, crawl spaces with exposure to outdoor air, or pump houses, heat tape (also called heat cable) provides active warming. Self-regulating heat tape adjusts its output based on temperature: it draws more power when the pipe is cold and less as it warms, so it does not overheat or waste electricity during mild weather.
Wrap the heat tape along the pipe according to the manufacturer's instructions (typically a straight run or a gentle spiral, never overlapping), then cover with pipe insulation over the top. The insulation retains the heat the tape produces. Plug the tape into a GFCI-protected outlet. Heat tape requires electricity, so it provides no protection during a power outage unless you have backup power.
Cold air enters the house through gaps around pipes, dryer vents, electrical conduit, and foundation penetrations. A small gap around a pipe where it passes through an exterior wall can channel freezing air directly onto the pipe, negating the insulation. Seal these gaps with expanding foam, caulk, or weatherstripping. Close foundation vents in winter (reopen them in spring to prevent moisture buildup). Keep garage doors closed.
On nights when temperatures drop below 20 degrees, open the cabinet doors under kitchen and bathroom sinks, especially those on exterior walls. This lets warm room air reach the pipes. Let one or two faucets drip slowly, choosing the faucet farthest from where water enters the house. The drip keeps water moving and relieves any pressure that ice formation might create.
Keep the thermostat at 55 degrees or above, even when the house is unoccupied. The small cost of heating is trivial compared to the cost of repairing a burst pipe and the water damage that follows.
Outdoor fixtures
Outdoor fixtures are the most exposed part of the water system and the easiest to protect. The damage they cause when they fail is disproportionate: a cracked outdoor spigot can leak water into the wall cavity behind it for hours before anyone notices.
Disconnect all garden hoses before the first freeze. A hose left connected traps water in the faucet body and the short pipe behind it, which can freeze and crack even a frost-free faucet. Shut off the indoor valve that feeds each outdoor faucet (if your house has one), then open the outdoor faucet to drain any remaining water. Leave the outdoor faucet open so any residual water can escape as it expands.
Install insulated faucet covers (foam or fabric) over each outdoor spigot. These are inexpensive, widely available at hardware stores, and easy to install with a loop and toggle or a drawstring. They provide a pocket of trapped air that insulates the faucet from wind and ambient cold.
Shut off the supply valve to the irrigation system and drain the lines completely. Most systems have manual drain valves at low points. For systems with no manual drain, use an air compressor set to 50 psi or less (higher pressure can damage sprinkler components) to blow out residual water. Open each zone sequentially until air flows cleanly from the heads with no water.
If you are not comfortable blowing out sprinkler lines yourself, most irrigation companies offer a winterization service for $50 to $150 depending on the system size and number of zones.
Well systems
If your household water comes from a private well, the pump and its above-ground components need freeze protection. The well itself is below the frost line and safe. The risk is in the equipment between the well and the house: the pump head (for jet pumps), the pressure tank, the pressure switch and gauge, and any above-ground pipe runs.
The pump itself is deep in the well, well below the frost line, and safe from freezing. Protect the above-ground components: wrap the pressure tank in an insulation blanket, insulate the pipe from the well head to the house, and insulate the pressure switch and gauge. If these components are in an unheated pump house or exposed well pit, add a thermostatically controlled heat source (a heat lamp, a low-wattage space heater rated for enclosed use, or heat tape on the pipes) to keep the space above freezing.
Jet pumps sit above ground, usually in a basement or pump house. The pump body and all associated piping need protection. Insulate the pump, the suction and discharge lines, and the pressure tank. If the pump is in an unheated outbuilding, a thermostatically controlled heat cable wrapped around the pump and pipes, covered by insulation, is the most reliable protection. As a backup, if you are winterizing a seasonal property and shutting the system down entirely, drain the pump, pressure tank, and all above-ground lines completely.
Manual hand pumps installed alongside a submersible pump (like the Simple Pump or Bison Pump) are designed with freeze protection in mind. Most include a weep hole drilled in the top drop pipe just below the frost line. After each use, water in the pump head drains back down through the weep hole to below the frost line, preventing ice from forming in the pump head. Leave the handle in the up position after use to assist drainage. If your frost line is deeper than the standard weep hole placement, most manufacturers will customize the hole location at no additional cost. See the deep well hand pump guide for details on pump selection and installation.
Rain collection
Rain barrels are among the most vulnerable outdoor water systems in winter. They sit above ground, exposed to wind and cold, and the spigot and ball valve components are the first things to fail when water inside them freezes and expands. The approach depends on how cold your winters get.
In climates with sustained freezing (weeks below 32 degrees): Drain the barrel completely before the first hard freeze. Disconnect it from the downspout. Open the spigot and all drain valves to let every drop of residual water escape. Store the barrel inverted, covered, or indoors. Reinstall it in spring after the danger of deep freeze has passed. A freeze-damaged barrel is usually not repairable.
In climates with occasional light freezes (a few nights per winter): Insulating the barrel and the spigot may be sufficient. Wrap the barrel in an insulation blanket and cover the spigot with an insulated faucet cover. Keep the barrel partially full, not completely full, to allow expansion room. Monitor the forecast and drain before any sustained freeze below 20 degrees. The rain barrel guide covers setup and maintenance in detail.
Stored water
Stored water in drums, jugs, and WaterBricks follows the same physics as pipes: water expands when it freezes, and sealed containers with no headspace can crack. But containers have one advantage that pipes do not. Thermal mass. A full 55-gallon drum starting at 55 degrees has enough thermal energy that it takes days of sustained below-freezing temperatures to freeze through, even in an uninsulated space.
The climate storage guide covers this topic in detail, including headspace guidelines, insulation strategies, and the power-outage catch. The short version: leave 10% headspace in every container, store below grade when possible, keep a one-week supply in smaller containers inside the conditioned house, and plan for the scenario where your garage storage freezes solid during a winter power outage.
When prevention fails
The first sign is usually a faucet that produces only a trickle or nothing at all on a cold morning. If you suspect a frozen pipe, act promptly. The goal is to thaw the pipe before the pressure builds enough to cause a burst.
If the pipe has already burst: Shut off the main water supply valve immediately. Open faucets to drain remaining water. Call a licensed plumber. Do not attempt to repair a burst pipe yourself if it is inside a wall, ceiling, or floor cavity.
Before winter arrives
Do these before the first freeze of the season. Most take 15 minutes or less individually. The full list is an afternoon project that prevents thousands of dollars in winter damage.
Disconnect and drain all garden hoses
Shut off indoor supply valves to outdoor faucets and drain the outdoor lines
Install insulated covers on all outdoor spigots and hose bibs
Insulate exposed pipes in crawl spaces, attics, garages, and along exterior walls
Install or inspect heat tape on previously frozen pipe runs
Seal air gaps around pipes at exterior wall penetrations
Drain and winterize irrigation or sprinkler systems
Drain and disconnect rain barrels (sustained freeze climates) or insulate them (mild freeze climates)
Insulate well pump head, pressure tank, and above-ground well piping
Confirm your main water shutoff valve turns freely (test it now, not during an emergency)
Verify headspace in all stored water containers (fill to no more than 90% capacity)
Move a one-week water supply in small containers inside the conditioned house
Set the thermostat no lower than 55 degrees, even when the house is unoccupied
Next steps
How heat, cold, and humidity affect stored water. Climate-adjusted rotation schedules and placement strategies.
Climate guide
Where the shutoff valve is, how water enters your house, and what to check before anything fails.
System guide
Backup plans for well owners, including hand pumps, generator sizing, and water testing for private wells.
Well guide
Continue reading
Disaster History
4.5 million homes lost power. Pipes burst across the state. The anatomy of a freeze catastrophe.
Preparedness
CO safety, single-room heating, pipe protection, and the full before-during-after winter storm plan.
Field Notes
Well pumps need electricity. What happens to your water supply when the power goes out.
Water
The roof math, barrel sizing, first-flush diverter, and the one-afternoon installation walkthrough.