What is the difference between epoxy coating and structural pipe lining?
Quick Answer
Epoxy coating sprays a thin layer of resin onto the inside of the pipe. Structural lining installs an actual new pipe inside the old one. They are sometimes marketed with similar words, but one is a surface treatment with a 3 to 10 year warranty and the other is a Class I structural repair with a lifetime warranty.
Two very different things with similar names
Coating, sometimes sold as "spray lining" or "brush coating," coats the pipe wall with resin. It can fill small surface defects and slow corrosion where it bonds well, and there are situations where that is a reasonable, budget-conscious choice. What it cannot do is add strength. Industry standards classify it as the lowest structural class, and if the host pipe cracks or moves, the coating cracks with it.
A cured-in-place structural liner is a resin-saturated tube inflated against the pipe wall and cured hard. The finished product is seamless, jointless, and strong enough to function as a standalone pipe. It restores flow, bridges cracks, and does not depend on the dying pipe around it.
How to tell which one you are being quoted
Ask two questions. What ASTM standard does the installation meet, and what is the warranty on both labor and materials? Structural lining answers F1216, F1743, or F2019, with a lifetime warranty. Coating answers with a shorter warranty and softer language. We install coatings ourselves where they genuinely fit, with an honest three-year warranty, and we will tell you plainly which situation yours is.
The Homeowner Takeaway
The word "lining" on a quote is not enough. Ask for the ASTM standard and the warranty. Structure comes with both. Coatings come with neither.
