How to Prevent Frozen Pipes and What to Do If They Burst

A single burst pipe dumps 400-600 gallons per hour into your home, causing tens of thousands in water damage within hours. Frozen pipes account for more insurance claims than any other plumbing problem, yet most freeze events are completely preventable.

Certain pipes freeze first. Knowing which locations face highest risk and how to protect them saves thousands in emergency repairs and water damage restoration.

Why Pipes Freeze and Burst

Water expands 9% when freezing. In a closed plumbing system, this expansion has nowhere to go. Pressure inside pipes increases from typical 60 PSI to over 200 PSI as ice forms and expands.

Pipes don't always burst at the frozen section. The pressure buildup occurs between the blockage and a closed faucet. Pipes often crack or burst at weak points downstream from the actual ice formation, making damage harder to predict and locate.

Metal pipes conduct cold efficiently, allowing exterior temperatures to affect interior water quickly. Plastic pipes insulate slightly better but still freeze when exposed to sustained cold without protection.

The actual rupture often occurs during thawing, not freezing. As ice melts, water pressure returns to normal but now has an escape route through cracks that formed under pressure. Returning home to flooding is common because pipes burst when warmth returns, not during the coldest period.

Temperature Thresholds

Pipes begin freezing when exposed to temperatures below 32°F for extended periods. The critical factor isn't just temperature but duration of exposure.

Brief dips to 25°F overnight rarely cause problems. Sustained temperatures below 20°F for six or more hours create serious risk. When temperatures drop to single digits over multiple days, freeze damage becomes almost certain for unprotected pipes.

Water movement delays freezing. Flowing water resists freezing even at below-freezing temperatures because movement prevents ice crystal formation. This is why letting faucets drip provides protection.

Wind chill doesn't directly affect pipes, but wind drives cold air into gaps, cracks, and vents that expose pipes to exterior temperatures. Windy conditions accelerate heat loss from pipes in crawl spaces, attics, and exterior walls.

High-Risk Pipe Locations

Exterior Walls

Pipes running through exterior walls face the most common freeze risk. The pipe sits in the wall cavity just inches from outdoor temperatures with minimal insulation protecting it.

North-facing walls get no solar warming and stay coldest. Kitchen sinks on exterior walls are particularly vulnerable because the cabinet blocks warm room air from reaching pipes.

Check your home's plumbing layout. Any supply line serving an exterior wall fixture has freeze risk.

Unheated Spaces

Pipes in garages, attics, crawl spaces, and basements without climate control freeze rapidly during cold snaps.

Garage pipes freeze first because garages typically have no insulation separating them from outdoor temperatures. Leaving garage doors open, even briefly, exposes pipes to freezing air.

Attic pipes freeze when insulation between living space and attic prevents warm air from reaching plumbing. The attic becomes essentially an outdoor space temperature-wise.

Crawl space pipes sit in the coldest part of most homes. Cold air settles, and crawl spaces often have vents that deliberately circulate outdoor air through the space.

Outdoor Faucets and Hose Bibs

Exterior faucets connect to interior plumbing. When water sits in the faucet and exposed piping, it freezes and can crack the valve body or pipe connection inside your wall.

Many older homes have standard outdoor faucets that don't drain automatically. Water remains in the valve even when shut off, guaranteeing freeze damage.

Mobile Homes

Mobile home plumbing runs through uninsulated undercarriages directly exposed to wind and cold. Freeze damage in mobile homes occurs at higher temperatures and happens faster than in traditional construction.

Skirting provides minimal protection unless insulated and sealed against air movement.

Insulation Methods

Pipe Sleeve Insulation

Foam pipe insulation costs $0.50-$2.00 per linear foot and installs in minutes. Pre-slit sleeves slip over pipes without disconnecting anything.

Insulation thickness matters. Half-inch walls provide minimal protection. Three-quarter inch to one-inch thick insulation offers meaningful freeze protection.

Cover the entire length of at-risk pipes. Leaving even a six-inch section unprotected creates a freeze point.

Tape sleeve seams closed. Gaps allow cold air infiltration that negates insulation benefits.

Insulation slows heat loss but doesn't prevent freezing indefinitely. At sustained sub-zero temperatures, insulated pipes eventually freeze without additional heat.

Heat Tape and Heat Cable

Electric heat tape maintains above-freezing temperatures actively rather than relying on insulation's passive protection.

Heat tape costs $0.75-$2.50 per foot and draws 5-10 watts per foot. A 10-foot section uses 50-100 watts, costing roughly $1-$2 monthly in electricity during winter.

Self-regulating heat cable adjusts output based on temperature, using power only when needed. Fixed-wattage tape runs constantly when plugged in, wasting energy during warmer periods.

Wrap heat tape in a spiral pattern along the pipe length. Follow manufacturer spacing specifications. Overlap creates hot spots that can damage pipes.

Never wrap heat tape over itself. The tape is designed to dissipate heat along the pipe, not into itself. Overlapping can create fire hazards.

Cover heat tape with insulation after installation. The insulation helps heat tape maintain temperatures more efficiently with less energy consumption.

Plug heat tape into GFCI-protected outlets only. Water and electricity don't mix, and plumbing areas have high moisture risk.

Newspaper and Temporary Insulation

In emergencies without proper materials, even 1/4 inch of newspaper provides significant protection for short cold snaps.

Wrap pipes in 6-8 layers of newspaper. Secure with tape or string. Cover the newspaper with plastic bags to keep it dry.

This provides enough insulation for overnight cold snaps but isn't suitable for extended freezes.

Blankets, towels, and foam pool noodles (split lengthwise) also provide temporary protection better than nothing.

Active Protection Methods

Faucet Dripping

Opening faucets to a steady drip prevents freezing through water movement and pressure relief.

Set faucets to drip at roughly five drops per 10 seconds. This wastes only 1-2 gallons over 24 hours but keeps water moving.

The drip doesn't need to be fast. A pencil-lead-thin stream wastes water unnecessarily. Slow, steady drips work fine.

Drip both hot and cold water. Many homes have separate supply lines that both need protection.

Dripping helps most when temperatures are forecasted between 20-32°F. At lower temperatures or for extended periods, dripping alone may not suffice.

The water wasted by dripping costs $2-$5 for a typical cold snap. Emergency pipe repairs and water damage cost thousands. The economics heavily favor dripping.

Opening Cabinet Doors

Kitchen and bathroom sinks on exterior walls need warm air circulation.

Open cabinet doors to let heated room air reach pipes under sinks. The temperature difference between inside cabinets (often 55-60°F) and the room (68-72°F) determines whether pipes freeze.

Remove stored items that block air flow. Cleaning supplies and trash cans can prevent warm air from reaching pipes.

A small fan directed into the cabinet improves circulation more than just opening doors.

Maintaining Indoor Temperature

Set thermostats no lower than 55°F when leaving home during cold weather. The money saved on heating bills can be lost many times over through a single freeze event.

Consistent temperature matters more than high temperature. Allowing indoor temperature to cycle widely stresses pipes as warmth recedes during thermostat setback periods.

If leaving for extended winter periods, either maintain heating or completely winterize by draining the system.

Garage Door Management

Keep garage doors closed during cold weather. Many people idle cars in garages with doors open, exposing plumbing to cold blasts.

Even 10 minutes with the garage door open during sub-freezing weather can start pipe freezing, especially in detached garages without insulated walls.

Sealing Air Leaks

Cold air infiltration around pipes causes more freezes than cold conductivity through walls.

Seal gaps where pipes penetrate walls between heated and unheated spaces. Use expanding foam insulation designed for this purpose.

Check for gaps around dryer vents, cable/utility penetrations, and anywhere exterior air might enter wall cavities.

Crawl space vents exist to prevent moisture buildup but also admit freezing air. Some experts recommend temporarily closing vents during extreme cold, though this risks moisture problems. A better solution is insulating pipes well enough that vents can remain open.

Winterizing Vacant Properties

Homes left unheated during winter must be completely winterized to prevent catastrophic damage.

Drain the System

Turn off the main water supply. Open all faucets and flush all toilets to drain water from pipes and fixtures.

Run faucets until water stops flowing completely. Air in pipes prevents freeze damage.

Pour RV antifreeze into toilet bowls, sink drains, and shower drains to protect traps. Water in traps will freeze and crack fixtures if not protected.

Drain the water heater. Attach a hose to the drain valve and run it outside or to a floor drain. Open the pressure relief valve to allow air in so water drains completely.

Turn off the water heater circuit breaker or gas supply valve.

Pressure Relief

Even with water drained, residual water collects at low points. Leave faucets open to prevent pressure buildup if this water freezes.

Notify Insurance

Many homeowner policies require notification when properties will be vacant for extended periods. Failure to notify can void coverage for freeze damage.

Some policies require someone to check the property every few days, even when winterized.

Thawing Frozen Pipes Safely

If water stops flowing and you suspect frozen pipes, act quickly before they burst.

Keep Faucets Open

Open the affected faucet fully. As you thaw the pipe, melting ice and water need escape routes. Trapped water creates the pressure that bursts pipes.

Apply Heat Gradually

Use electric heating pads wrapped around pipes, hair dryers, or portable space heaters placed near (not touching) pipes.

Heat the section of pipe closest to the faucet first, working backward toward the frozen area. This allows melting water to drain rather than being trapped behind ice.

Never use open flames, propane torches, or other high-heat sources. These can boil water inside pipes, create steam pressure that bursts pipes, or ignite nearby materials.

Even heat guns used for paint stripping produce excessive heat. Stick with hair dryers and heating pads.

Call for Help

If you can't reach the frozen section, pipes are inside walls, or you're uncomfortable working with plumbing, call a plumber immediately.

Emergency plumbing calls cost $200-$500, but burst pipe damage costs $5,000-$50,000 for repairs and restoration.

What to Do When Pipes Burst

Shut Off Water Immediately

Locate your main water shutoff valve now, before emergencies happen. Every adult in the household should know its location.

Turn the valve clockwise until fully closed. This stops water flow from the main supply line.

If you can't reach the main valve or it won't turn, call your water utility emergency number. They can shut off water at the street.

Turn Off Power

If water is flooding near electrical outlets, circuit breakers, or appliances, shut off power to affected areas at the circuit breaker panel.

Don't walk through standing water to reach electrical panels. Call an electrician or fire department for assistance.

Document Damage

Take photos and videos of all water damage before cleanup. Insurance claims require documentation.

Call Plumber and Insurance

Contact an emergency plumber immediately to repair the burst pipe. Call your insurance company to start a claim for water damage.

Most policies require prompt notification. Delays can complicate or invalidate claims.

Remove Water

Use wet/dry vacuums, mops, and towels to remove standing water as quickly as possible. Water damage accelerates with time.

Move furniture and belongings to dry areas. Lift area rugs and remove wet padding.

Run fans and dehumidifiers to dry affected areas. Mold begins growing within 24-48 hours in wet conditions.

Professional water damage restoration costs less when started immediately rather than after mold and structural damage develop.

Protecting Specific Problem Areas

Outdoor Faucets

Install frost-free hose bibs that drain automatically when shut off. The valve mechanism sits 6-12 inches inside the wall where warm air prevents freezing. Water drains from the exterior spout when closed.

Frost-free faucets cost $15-$40 and install in 30-60 minutes. They're the single best freeze protection investment.

Disconnect garden hoses before freezing weather. Attached hoses prevent proper drainage from frost-free faucets, negating their protection.

Install exterior faucet covers. These insulated caps cost $3-$8 and provide additional protection for both standard and frost-free faucets.

Swimming Pool and Sprinkler Lines

Blow out irrigation systems with compressed air before winter. Standing water in sprinkler lines freezes and cracks pipes and valves.

Professional blowouts cost $75-$150. DIY requires an air compressor capable of maintaining 50-80 PSI.

Pool plumbing should be winterized by pool professionals. The complex valves and equipment need proper procedure to prevent expensive freeze damage.

Water Heaters in Garages

Tank water heaters in garages can freeze when tank temperature drops below freezing despite full tanks of water.

Insulate tanks with water heater blankets. These cost $20-$40 and reduce heat loss by 25-45%.

Build insulated enclosures around water heaters in very cold climates. Leaving one side open allows access while protecting three sides.

Install a small space heater on a thermostat in water heater enclosures. The heater activates only when temperature drops to dangerous levels.

Long-Term Solutions

Rerouting Vulnerable Pipes

Pipes in exterior walls can be relocated to interior walls during renovations. This permanent solution eliminates freeze risk.

Rerouting pipes costs $500-$2,000 depending on complexity. For chronically problematic locations, this investment pays off through prevented damage.

Improving Insulation

Adding insulation to exterior walls, attics, and crawl spaces protects pipes indirectly by maintaining warmer ambient temperatures around plumbing.

Blown insulation in exterior walls costs $1.50-$3.00 per square foot. For walls with repeated freeze problems, this improves both energy efficiency and freeze protection.

Installing Recirculation Systems

Hot water recirculation pumps keep water moving continuously through hot water lines. The movement prevents freezing while also providing instant hot water at fixtures.

These systems cost $300-$800 installed. They work well for vacation homes where maintaining heat is expensive but keeping pipes from freezing is essential.

Regional Considerations

Mild Climates

Homes in areas where freezing weather is rare typically lack adequate pipe protection. These regions face the highest freeze damage costs when unusual cold strikes.

Check 30-year weather records. If temperatures below 20°F have occurred even once in three decades, protect vulnerable pipes. That rare freeze event will eventually repeat.

Cold Climates

Homes in consistently cold climates usually have proper pipe placement and insulation. Problems arise when homeowners reduce heating to save money or when extreme cold exceeds normal design parameters.

Temperatures below -20°F stress even well-designed systems. Take extra precautions during polar vortex or arctic blast events.

Cost Comparison

Prevention Costs

Insulating all vulnerable pipes: $50-$200 in materials Heat tape for problem areas: $30-$100 installed Frost-free faucet installation: $75-$150 each Professional winterization for vacant home: $150-$300

Total prevention investment: $300-$750 for thorough protection

Damage Costs

Emergency plumber call to thaw frozen pipes: $200-$500 Burst pipe repair in accessible location: $400-$1,000 Burst pipe repair in walls/ceiling: $1,000-$5,000 Water damage restoration (including mold): $3,000-$25,000 Average insurance claim for freeze damage: $18,000

The investment in prevention pays for itself many times over by preventing a single freeze event.

The Bottom Line

Pipes freeze in predictable locations under predictable conditions. Protecting those locations with basic insulation and heat tape costs less than $500 for most homes.

Frozen pipes that burst cause average damage of $18,000 per incident. The return on prevention investment exceeds 3,000% by avoiding a single burst pipe.

Know which pipes in your home face highest risk. Protect them before cold weather arrives. When extreme cold is forecast, take active steps like dripping faucets and opening cabinets.

The time to prepare for pipe freezing is now, not during a cold snap when plumbers are overwhelmed with emergency calls and supplies sell out at hardware stores.