By Sean Comerford, Manager, Inside Sales and Tech Support, Oatey Co.
Table of Contents
As winter sets in, plumbing professionals prepare for one of the season’s busiest and most unpredictable challenges, frozen pipes. These incidents can cause significant damage to homes and necessitate urgent, time-sensitive repairs.
To prevent unwelcome surprises, understanding why pipes freeze, which materials perform best, and how to apply proper insulation and circulation strategies helps contractors get ahead of the problem. In doing so, they can ensure their customers enjoy a comfortable and worry-free winter.
The High Stakes of Frozen Pipes
Frozen pipe prevention is a critical issue in the plumbing industry, particularly in regions that experience prolonged sub-zero temperatures. When water freezes, it expands, creating pressure that can rupture pipes and cause significant property damage once thawing begins. Even if a pipe doesn’t burst, freezing halts water flow, resulting in disruptions to essential services.
For contractors, frozen pipes are unpredictable and difficult to schedule around. Rapid temperature shifts often trigger waves of emergency service calls. Preventive education and service offerings are therefore vital to maintaining strong customer relationships and keeping homes protected from damage.
What are the Earliest Signs of a Frozen Pipe?
The earliest indicator of a frozen pipe is typically reduced or halted water flow. Homeowners may notice that water trickles or stops completely from a faucet, signaling that a section of pipe has begun to freeze.
Once thawing begins, any cracks or splits become evident, leading to leaks or bursts that can quickly escalate into major water damage.
High-Risk Areas and Common Oversights
Certain installation conditions make pipes more vulnerable to freezing:
- Exterior walls or unheated spaces: Pipes exposed to low temperatures, such as in attics, crawl spaces, and basements, face the greatest risk.
- Aging insulation: Over time, insulation deteriorates or shifts, leaving sections of pipe exposed. Moisture accelerates this breakdown, particularly in crawl spaces or areas prone to dampness.
- Lack of airflow control: In commercial settings, adding vented ceiling tiles or vented access panels can help circulate warm air around pipes during temperature drops.
- Outdoor fixtures: Hose bibs, or sillcocks, must be shut off and drained before winter. Frost-proof models offer additional protection, but not all homes are equipped with them.
Simple inspections, especially in older buildings, can reveal these vulnerabilities before a freeze sets in.
Best Practices for Frozen Pipe Prevention
While there is no single product that eliminates freezing risk, several materials play a key role in prevention:
Insulate thoroughly
Foam tubing (photo) is a standard and effective solution, especially when properly sealed with tape to close gaps and block cold air. Foam pipe insulation with tight seams prevents cold air infiltration and condensation buildup. In crawl spaces or basements, inspect for cracks, gaps, or drafts that allow cold air to reach piping.
While commercial plumbing codes typically require pipe insulation, residential regulations vary. Regardless of code requirements, insulating both cold and hot water lines is a best practice to improve energy efficiency and reduce the risk of freezing.
For extremely low temperatures, typically below -20°F, insulation should be paired with heat tape to provide additional protection.
Use antifreeze correctly
Used only in unoccupied or winterized systems, antifreeze provides protection where water flow is halted, such as in seasonal homes or hydronic heating loops. Hercules® Cryo-Tek™ Original Antifreeze is a ready-to-use 45% Virgin Propylene Glycol formula. It is non-toxic and designed for hydronic heating and cooling closed-loop systems, most solar heating systems, snow melts, radiant heat, and general plumbing systems.
Note: The virgin propylene glycol used in Cryo-Tek is “GRAS” (Generally Recognized As Safe) for incidental contact with food. Any Cryo-Tek product can be added to protect pipes from freezing and bursting. It also prevents freeze-ups in chiller systems, recreational vehicles, seasonal homes, mobile homes, trailers, boats, sprinkler systems, and industrial use.
This antifreeze can be poured into toilet bowls and tanks, keeping the flapper/seals in the toilet tank lubricated and preventing them from dry rotting. It should also be poured into all showers, tubs, floor, and sink drains — basically, any fixture with a trap. This will ensure that water in the traps does not freeze, while preventing evaporation and maintaining the trap seal.
Each method serves a different purpose and may be combined for enhanced protection in high-risk installations.
Use heat tape
This low-voltage, electric wire wraps around pipes and generates consistent warmth to prevent freezing in extreme conditions.
Keep water moving
Water in motion is far less likely to freeze. Allowing a small, steady flow through vulnerable pipes maintains movement and reduces the risk of ice buildup. In larger systems, recirculating pumps can maintain water flow throughout the plumbing network, even when water isn’t being actively heated, mimicking the same protective effect.
Each of the above methods serves a different purpose and may be combined for enhanced protection in high-risk installations.
Working with Older Homes
In older homes with outdated insulation or exposed plumbing, communicate preventive options clearly to customers. Recommendations might include rerouting vulnerable lines, upgrading insulation, or applying supplemental heating solutions.
Establishing a preventive inspection service, such as an annual plumbing system inspection, can be a practical offering for contractors. A brief walkthrough to identify exposed pipes or deteriorated insulation not only reduces emergencies but also builds trust and recurring service opportunities.
Material Performance in Extreme Cold
Pipe material has a direct impact on freeze resilience.
- CPVC is the most susceptible to cracking under pressure due to its rigidity.
- Copper performs better but can still split after repeated stress. According to the Copper Development Association, copper and copper alloys retain a high degree of ductility and toughness at subzero temperatures. In fact, copper alloys become stronger and more ductile as the temperature goes down, retaining excellent impact resistance to 20 K (-253°C or -424°F).
- PEX (crosslinked polyethylene) offers the highest resistance because of its flexibility, it can expand up to twice its diameter and return to its original shape after thawing. According to the 2020 Plastics Pipe Institute (PPI) Technical Report TR-52, PEX tubing can expand up to three times its diameter under freeze conditions without rupture and return to its original dimensions after thawing.
The material properties of PEX pipe and tubing provide it with an inherent benefit when subjected to freezing conditions. PEX materials have a lower thermal conductivity than metallic piping materials, which reduces the thermal exchange rate, which can extend the time required to freeze the fluid within the system.
If freezing of fluid within PEX does occur, the elastic nature of PEX materials — at temperatures even below -40°F (-40°C) — enables circumferential and axial expansion that correlates to the increase in volume of the fluid during a freezing event.
Although increasing pipe diameter can delay freezing, it’s rarely a practical design adjustment for standard residential fixtures. The focus should instead be on proper placement, insulation, and material selection.
Long-Term Effects of Freeze–Thaw Cycles
Even if pipes survive a freeze, repeated freeze -thaw cycles can degrade their structural integrity over time. Each cycle weakens the pipe walls, particularly in rigid materials such as copper or CPVC. Failures may not occur immediately but can emerge after several winters, turning minor stress points into full-scale ruptures.
Practical Prevention Measures for Homeowners
Plumbers can help homeowners implement small but effective habits that prevent frozen pipes during cold snaps:
- Keep cabinet doors open under sinks located on exterior walls to allow warm-air circulation.
- Run a small fan to move air through confined or cold-prone areas.
- In extreme cold, let faucets run slightly to keep water flowing.
These steps are especially effective in older homes or areas with minimal insulation.
Bottom Line
Frozen pipe prevention combines preparation, product knowledge, and ongoing inspection. With the right materials and maintenance, both homeowners and contractors can avoid midwinter emergencies and keep water systems running smoothly.
About the author: Sean Comerford is Manager, Inside Sales and Tech Support at Oatey Co. He is a third-generation tradesman with nearly 20 years of plumbing experience, including the lead plumber for commercial/residential new-construction, service and fire protection jobs. He holds a State of Ohio Fire Protection License for Sprinkler and Standpipe.
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