Before it leaks.......ok, in all seriousness, what bear II said. If its getting brittle, and especially if you begin to see cracks. Caulking should be fairly soft and pliable, which absorbs the shocks and flexes of the trailer.
Jayco Designer 30 RKS Medallion pkg, Trail Air pin
'05 F350 6.0 PSD CC 4x4 DRW LB B&W Companion, Edge Insight
โCertainly, travel is more than the seeing of sights; it is a change that goes on, deep and permanent, in the ideas of living." Miriam Beard