Limitations of Epoxy Pipe Lining

Epoxy Lining is a general term for a variety of different plastic resins used on hot and cold water supply pipes, sprinkler lines, HVAC piping, gas lines and certain drain, waste and vent piping. The National Sanitation Foundation (NSF) and U.S. Environmental Protection Agency (EPA) have certified some epoxy linings for carrying potable drinking water. Epoxy resins are generally not certified as a “structural improvement” to the existing piping system.

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The Epoxy Paradox:

…The question arises that if an application should fail a test or inspection, what is the contingency plan to remediate the flaw? How will the epoxy be removed and how will the recoating be applied? If a single failure is found, what test sampling strategy must be applied to give a high likelihood that no other flaws exist in the system? Under what warrantee claim would a failed test be covered and to what extent will coverage be warranted?

The serviceability issue is not trivial. Homeowners must be comfortable with the idea that no further modifications, maintenance, or improvements can be made on their current potable water system.

Double Jeopardy: When an epoxy failure does happen, it is likely to occur at the location where the pipe is already at its weakest; pitted areas and threads. As such, a poorly applied epoxy liner could weaken a pipe considerably. The result could be a catastrophic high-volume pipe failure requiring a high insurance payout, which would not otherwise be attributed to epoxy coating.20

Epoxy Lining Conclusions

The overwhelming amount of risk associated with epoxy lining, coupled with observations of failed installations and their consequences, has led the authors to conclude that epoxy lining pipes within the building envelope is not a comparable alternative to pipe replacement. Before making an investment decision, it is always advisable for a community to explore all its options, including a repipe, to ensure their property is making the most informed decision possible about fixing its leaking pipes.