The short answer
Location Matters Most
Where a pipe runs in your home has the biggest effect on freezing risk. Pipes in unheated spaces, such as attics, crawl spaces, garages, or along exterior walls, are exposed to colder air. Even a small draft from a vent or a gap in insulation can drop the temperature around the pipe below freezing.
Pipes that run through cabinets under sinks, especially those on outside walls, also face higher risk because cabinet doors block warm room air. If you have a pipe in a spot that stays cold, consider opening cabinet doors during freezing weather or adding insulation. The pros often find that the most vulnerable pipes are the ones tucked into the coldest corners of the house.
Material Affects Freezing Speed
The material of the pipe changes how quickly it loses heat. Metal pipes, like copper or steel, conduct heat well, so they lose warmth fast and freeze sooner than plastic pipes. Plastic pipes, such as PEX or PVC, resist heat transfer better, giving them a bit more time before ice forms.
However, plastic pipes can still freeze and may burst if the ice expands. No pipe is immune. If you have older metal pipes in an unheated area, they need extra attention. Insulating them or adding heat tape can help, but the pros can show you the right approach for your specific piping.
- Copper and steel pipes freeze faster than plastic
- PEX and PVC resist freezing a little longer
- Smaller diameter pipes freeze quicker than larger ones
- Insulation slows heat loss but does not prevent freezing
- Heat tape can help, but must be installed correctly
Exposure and Insulation Gaps
Pipes that are exposed to outdoor air, like those running along an exterior wall or through a vent, are more prone to freezing. Even if a pipe is inside, gaps in insulation or missing seals can let cold air reach it. A pipe in an unheated crawl space or attic may also be colder than one in a heated living area.
Check for holes or cracks around pipes where they enter your home. Sealing these gaps with caulk or foam can reduce cold air flow. Adding pipe insulation, especially around bends and joints, helps keep the pipe warmer. The pros can identify weak spots you might miss, but you can start by looking for visible gaps.
Water Flow and Usage
Pipes that are used less often are more likely to freeze because water sits still in them. Moving water has more energy and is less likely to freeze quickly. A pipe that runs to an unused bathroom or an outdoor spigot is at higher risk during a cold snap.
If you have a pipe that is not used regularly, consider draining it before winter. For pipes that must stay active, letting a small trickle of water run during extreme cold can help, but this uses water and may not be practical. The pros can advise on the right strategy for your home, but the key is to keep water moving or drain the line.
Prevention and What to Do
You can reduce freezing risk by insulating pipes in cold areas, sealing air leaks, and keeping your home heated to a consistent temperature. If a pipe does freeze, you may notice no water flow or a hissing sound when you turn a faucet. Do not use an open flame to thaw a pipe, as this can cause a fire.
Instead, use a hair dryer or a space heater to gently warm the pipe. If a pipe bursts, turn off your main water shutoff valve right away. Then call the pros for water damage cleanup. Keep your shutoff valve location written down so you can act fast. For burst pipes, see the related services below.
- Insulate pipes in unheated areas
- Seal gaps and cracks around pipe entries
- Let faucets drip during extreme cold
- Drain outdoor lines before winter
- Know where your main shutoff valve is
- Call the pros if a pipe bursts
Water damage does not wait
Water keeps spreading into floors and walls, so it is worth acting early. Calls are answered 24/7.
Call Now (480) 898-4279Frequently asked questions
Do plastic pipes burst when frozen?
Yes, plastic pipes can burst when water freezes and expands. Though they resist heat loss longer than metal, the ice still expands and can crack the pipe. If you suspect a frozen pipe, act quickly to thaw it gently or call a plumber.
Should I leave a faucet dripping in a cold snap?
Letting a small trickle of water run can help prevent freezing because moving water is less likely to freeze. This is most useful for pipes in unheated areas. It uses water, so use it only during extreme cold and for pipes at highest risk.
What should I do if a pipe bursts?
Turn off your main water shutoff valve immediately to stop the flow. Then call the pros for water damage cleanup. They can extract water, dry the area, and repair drywall or flooring. Do not delay, as water damage worsens quickly.