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 .