Plaster life expectancy -- with a high quality job -- is often given as 10 years. I've seen it last longer than that, but it depends on water chemistry, installer skill . . . and some unknown factors.

Plaster composition has changed over the past 25 years, due to a variety of regulations. There's no final conclusion about the effects of these changes, but the consensus seems to be the current composition is not as durable as what was installed in older pools.

Paint life varies. Kelley Technical lists their epoxies as up to 7 years. But when *I* have used it -- heavy coat of Gunzite followed by a heavy coat of Zeron -- I've gotten 5 years. The results I've seen from OTHER contractors trying to use it have ranged from 1 - 3 years, either because of application errors, or because they were trying to go too thin.

Using epoxy paint requires LESS skill than plaster. But, plaster can be applied under a wider range of weather conditions than epoxy paint can be, and application requires are not quite so picky.

So . . . neither choice is 'ideal'.

One point to consider: you can do epoxy yourself, if you follow the directions. You cannot do a good job with plaster yourself; the application skill has to be acquired with considerable practice in mixing and using a trowel rapidly and effectively.