An integrated air barrier assembly is provided as an integral product in which a fastener-sealing layer is secured between opposed surfaces of a board and an anti-blocking facing layer. The assembly exhibits good fastener sealability, including for larger self-drilling screws. The anti-blocking facing layer maintains the fastener-sealing layer inward of the environment and prevents blocking or sticking of the assembly when stacked. In some embodiments, the anti-blocking facing layer can be a metal film or foil, which can reflect heat away from the fastener-sealing layer, thereby maintaining a lower temperature on the fastener-sealing layer. In some embodiments, the board can be an insulating layer or wood layer. The assembly can be readily installed in a single step during construction.