A system and method of incorporating and coating antimicrobial preparations for building materials by incorporating the antimicrobial preparation into a base material; and forming the base material into a polymer blend and by dispersing an antimicrobial preparation agent evenly in a compatible solution; applying the compatible solution to the building material; and curing the building material to remove the solution. In accordance with the present invention, the building materials that may be used are, for example, house wrap materials, flashing materials, self-adhering flashing materials, sill pans, below grad moisture barriers, subfloor underlayment, roof decks, thresholds, shower pans, material behind or below tile, vapor barriers and any combination thereof. The resulting products will contain antimicrobial preparations distributed throughout the material or coated with the antimicrobial preparations to inhibit the growth of microbes on exterior surfaces and interior regions of the building material.