Abstract: A building article incorporating a biocidal agent, such as copper oxine, that inhibits the growth of mold, fungi, algae, mildew, bacteria, lichen, and other undesirable biological growth is provided. The biocidal agent can be a biocide, fungicide, germicide, insecticide, mildewcide, or the like. The biocidal agent can be interspersed throughout the matrix of the article; applied as a surface treatment to the article; or applied as a treatment to the fibers reinforcing the article. The building article can include tile backer boards, decks, soffits, trims, decking, fencing, roofing, cladding, sheathing, and other products. The building article can also include a variety of different composite materials such as cement, gypsum, wood, and wood/polymer composites.