'RoyGBivUV" noted that the item damaged was a "gutter extension". This would be on the side of the unit. I agree that the Dicor sealants made for flat surfaces is very good but in this case wouldn't a silicone sealant, non-paintable at that, be a better sealant? AI installed gutter extensions on my unit and used a silicone sealant on these. I'm not sure how the Dicor, especially the 501 Dicor, would work on a vertical surface.