Ultrakote's ULTRAFLEX XP is specially designed for use over Ultrakote One Coat and Premix stucco basecoats. All Ultrakote finishes contain additives to resist mildew, algae, and fungus. ULTRAFLEX XP may be used either on the interior or the exterior, over cementitious or non-cementitious base coats, prepared concrete or masonry, prepared drywall, prepared painted surfaces or EIFS synthetic stucco systems.