There are a number of shield barrier products available to wrap your pressure treated deck framing materials with to prevent water damage and hardware corrosion. Most of these products are sold as rolls of self adhesive peel and stick flashing tape. Some builders install this material over the tops of joists for extra insurance against rot caused by water. Other builders use this material as a barrier between ACQ pressure treated wood and hardware to prevent corrosion.
These products are usually not necessary because the framing material is already chemically treated for exterior use and all deck hardware should be triple zinc galvanized or stainless steel to prevent corrosion. However it is an option for those who want extra protection against water damage or are installing decks in areas with large amounts of standing water such as pool decks.