Exemplary methods and assemblies for preventing corrosion of metal connector devices, e.g., zinc-galvanized joist hangers and fasteners, used for assembling outdoor structures such as decks from wood components pretreated with alkaline copper quat (ACQ), ammoniacal copper quat (ACQ-B), copper azole (CA), or mixtures thereof. Membrane barriers separate metal from wood, and seal around fasteners thus minimizing corrosion of the connector devices and fasteners.