You ask for thoughts. My thoughts are it's aluminum, it will probably outlast you by a few hundred years. Keep up the lap sealant as the joints are where you are going to have a problem. If you are concerned about the longevity of the actual aluminum put a coat of paint on it. Anything else like EPDM roof coating is a waste of money.
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2001 Suburban 4x4. 6.0L, 4.10 3/4 ton **** 2005 Jayco Jay Flight 27BH **** 1986 Coleman Columbia Popup