I recently discovered my 15 yr + roof is Masonite. Living in CO (relatively no humidity) I've had no problem with the roof. The edges are starting to curl a little and my remodeling contractor feels I should "treat" it with something though he' never encountered this type of material in a roof application. Do I, can I paint, stain or waterseal the roof to try to prolong it's life?? Widow needs advice--- THANKS!!