Why pipes freeze and burst
Water expands as it freezes. When water inside a pipe turns to ice, the expanding ice creates pressure within the pipe. The pipe does not always burst where the ice forms. Often, pressure builds between the ice blockage and a closed faucet, and the pipe splits in that section.
Pipes most at risk are those in unheated or poorly insulated spaces, such as crawlspaces, attics, garages, exterior walls and under sinks on outside walls. Outdoor hose bibs, irrigation lines and pipes near foundation vents are also vulnerable. Homes left unheated during cold weather face higher risk throughout.
A frozen pipe may not show obvious signs until it thaws. Once the ice melts, water can pour from a split pipe, damaging walls, floors, ceilings and belongings. That is why it is important to find and thaw frozen pipes carefully, with the main water shutoff location known in advance.
Frozen pipes can also affect other systems. Water heater supply lines, boiler piping and outdoor backflow preventers may be damaged by freezing. Our Water Heater Repair and Backflow Testing services address those components when cold weather has affected them.
Signs you may have a frozen pipe
If you notice these during very cold weather, act quickly.
- No water or a trickle from a faucetReduced or no flow from a fixture during cold weather often means a pipe feeding it is frozen.
- Frost on exposed pipesVisible frost on pipes in crawlspaces, basements or under sinks indicates freezing conditions.
- Toilet not refillingA toilet that will not refill may have a frozen supply line, especially on an exterior wall.
- Strange odors from drainsFrozen or blocked drain lines can cause odors to back up into the home.
- Bulging or cracked pipe sectionsVisible bulging or cracks indicate the pipe has been stressed by freezing and may leak when it thaws.
- Water stains or dripping after a cold snapLeaks that appear as temperatures rise often come from pipes damaged during freezing.
How we handle frozen and burst pipes
The priority is stopping damage, then restoring water safely.
Shutoff and assessment
If a pipe has burst, we confirm the main water valve is closed and assess the extent of the damage.
Locating frozen sections
We trace the affected lines to identify where freezing occurred, checking exposed pipes in cold spaces and walls.
Safe thawing
Frozen pipes are thawed gradually using safe methods such as warm air or pipe heating equipment, never open flames, while watching for leaks.
Repair
Burst or damaged sections are cut out and replaced with new pipe, and fittings are tested for leaks.
Prevention recommendations
We point out vulnerable pipes and recommend insulation, heat cable, rerouting or other steps to reduce the risk of future freezing.
Pipe frozen or burst?
If a pipe has burst, shut off the main water valve immediately and call. If a pipe is frozen, open the affected faucet and call before it thaws.
What affects frozen pipe repair scope
Accessibility is a major factor. Pipes exposed in basements or crawlspaces are easier to thaw and repair than those inside finished walls or ceilings. Opening drywall to reach a damaged pipe is sometimes necessary, and restoration may involve other trades.
The extent of damage also matters. A single split section is a straightforward repair. Multiple damaged sections or water damage to the structure require more work. Water damage restoration, such as drying and repairing drywall or flooring, is typically handled by restoration specialists, and we can explain what is needed.
What to do right away
If a pipe bursts, close the main water shutoff valve immediately. Turn off electricity to areas where water is near outlets or appliances if it is safe to do so. Move valuables away from the water and begin removing standing water to limit damage.
If you suspect a pipe is frozen but not burst, open the faucet it feeds so water can flow as it thaws, which relieves pressure. Warm the area with a space heater kept at a safe distance or by opening cabinet doors to let warm air reach the pipe. Never use an open flame to thaw pipes, as it can cause fires and damage the pipe.
Preventing frozen pipes
Insulating exposed pipes in crawlspaces, attics, garages and exterior walls is one of the most effective prevention steps. Pipe insulation sleeves are inexpensive and simple to install on accessible pipes. In very cold areas, thermostatically controlled heat cable provides additional protection for especially vulnerable pipes.
Sealing air leaks near pipes, such as gaps around foundation vents, sill plates and utility penetrations, prevents cold air from reaching them. Disconnect garden hoses and shut off and drain outdoor faucets before winter. Frost-proof hose bibs place the shutoff valve inside the heated space, reducing freeze risk.
During extreme cold and when away
During extreme cold, letting faucets on exterior walls drip slightly keeps water moving and can help prevent freezing. Opening cabinet doors under sinks allows warmer indoor air to reach pipes. Keeping the thermostat set to a consistent temperature, day and night, helps protect pipes in colder areas of the house.
If you will be away during cold weather, keep the heat on at a safe minimum temperature and consider shutting off the main water supply and draining the lines. Asking someone to check the house periodically can catch problems early. Homes with heating systems that may fail during a cold snap benefit from maintenance before winter, and our Boiler Repair and Furnace Replacement pages describe heating services that help keep pipes protected.
Choosing the right repair material
When a burst section is replaced, the repair material should suit the location and the existing system. Copper, PEX and CPVC each have their place. PEX tolerates freezing better than rigid pipe because it can expand slightly, although no pipe material is immune to damage from repeated freezing. Transitions between materials are made with fittings designed for that purpose.
Where a pipe has frozen more than once in the same location, rerouting it into a heated space or adding insulation and heat cable is usually better than repeating the same repair each winter. We explain the options and recommend the one that addresses the cause rather than just the symptom.
Frozen pipe questions
How do I know if a pipe is frozen?
Common signs include no water or reduced flow from a faucet, frost on exposed pipes and a toilet that will not refill during very cold weather. Pipes on exterior walls and in unheated spaces are most at risk.
Can I thaw a frozen pipe myself?
You can try gentle methods such as opening the faucet, warming the area with a space heater kept at a safe distance or using a hair dryer. Never use an open flame. If you cannot locate the frozen section or the pipe is damaged, call a plumber.
What should I do if a pipe bursts?
Shut off the main water valve immediately, turn off power to affected areas if it is safe, move belongings away from water and call for repair. Quick action limits damage.
Will insurance cover burst pipe damage?
Coverage varies by policy and circumstances. Many policies cover sudden water damage from burst pipes but may exclude damage from neglect. Check with your insurer about your specific policy.
How can I prevent pipes from freezing?
Insulate exposed pipes, seal air leaks near pipes, disconnect hoses and drain outdoor faucets, keep the heat on during cold weather and let faucets on exterior walls drip during extreme cold.
Related plumbing and heating services
Cold weather affects plumbing, heating and backflow equipment.