Section 3285.308 - Manufactured piers(a) Manufactured piers must be listed and labeled and installed to the pier manufacturer's installation instructions. See § 3285.303(d)(2) for additional requirements.(b) Metal or other manufactured piers must be provided with protection against weather deterioration and corrosion at least equivalent to that provided by a coating of zinc on steel of .30 oz./ft.2 of surface coated.