Will the PEX Pipe Break If It Freezes?

PEX (cross-linked polyethylene) pipe is highly regarded for its flexibility and superior freeze resistance when compared to rigid materials such as PVC or copper. Despite its resilience, freezing temperatures can still pose a risk under certain conditions. This article will explore the impact of freezing on PEX pipes, including their flexibility, ability to withstand pressure, the importance of proper insulation, and how to properly thaw frozen pipes.

PEX Pipe Flexibility and Freeze Resistance

One of the key benefits of PEX pipe is its excellent flexibility. This allows the pipe to expand slightly when the water inside freezes, which significantly reduces the risk of the pipe breaking. PEX can expand to accommodate the expansion of freezing water, thereby reducing the chances of rupture. However, if the expansion is excessively great or if the pipe is restricted in any way, there is a risk of cracking or a rupture.

Pressure and Bursting

When PEX pipes freeze to a significant extent, they can rupture, particularly if they are under pressure. The formation of ice can cause the pipe to expand, and if the expansion is too great, it can result in a burst. Given this, it is advisable to drain the system thoroughly if freezing temperatures are expected. Proper drainage will release the pressures built up inside the pipes, helping to prevent damage.

Insulation and Temperature Control

The risk of freezing can be mitigated through proper insulation and maintaining a higher ambient temperature. Insulating PEX pipes is crucial, as it helps to prevent the water from freezing in the first place. In areas where PEX pipes are located, it is also essential to keep the temperature above freezing. This can be achieved through heating tapes, heat mats, or even simple household measures like keeping the area warm.

Thawing Frozen PEX Pipes

Should PEX pipes become frozen, thawing them without causing damage is possible, provided the pipes are not under pressure. Slowly and steadily apply heat to the frozen section of the pipe. This can be done using a hairdryer, warm towels, or gentle heat from a heating pad. It is important to avoid sudden application of heat, as this can cause sudden expansion and potentially lead to damage.

From Real-World Experience

My personal experience with PEX pipes in extreme conditions corroborates its durability. In the winter of 1997, the PEX pipes and water tank froze solid. Despite the severe freeze, the PEX pipes and fittings remained intact and functional. The brass fittings also remained in place today, serving as a testament to the material's resilience. PEX is indeed a marvel of modern plumbing, offering unparalleled strength in both heat and cold.

While PEX is generally more elastic than metallic piping and more resistant to freeze breakage than copper or hard plastic, it is not entirely immune to damage under certain conditions. Fittings, which are typically made from copper, can still be potential weak points. However, the overall resistance of PEX to freezing is a significant advantage, making it a reliable choice for many plumbing applications.