Some facts on fabric.
there is no failure criteria for ceconite, the punch test using the Maule tester is for cotton systems.
There are 3 basic fabric systems, dope over cotton, dope over ceconite, and ura system over ceconite.
Purest use dope over cotton.
The old ceconite manual uses dope on ceconite.
the newest of the bunch is a ura system, on ceconite.
there are three major suppliers for the ura systems, Polyfiber, Stewarts, and Airtech.
Dope and Polyfiber use a reflective coating to stop UV light from entering the coatings and attack the fabric.
Airtech is the fire proof system used by many agcroppers.and the Stewarts use a UV blocker formulated into the system in both the top coat and base coat, these systems do not need a silver or aluminum reflective coating to stop UV light.
All that said, the life of any system is based upon how well it was applied, and how well it was cared for in service.
To answer your question the life of a well applied and cared for ura system, is expected to exceed 50 years.
Tom D. http://www.whidbey.com/fairchild-nc19143/
Republican / Democrat, same stink, different pile.