The present invention relates to, inter alia, methods for the treatment of wallboards and the treated wallboards. In particular, the invention relates to the treatment of wallboards with a fungicidally effective amount of a strobilurin or strobilurin-type fungicide. In a particular embodiment the fungicide is azoxystrobin. The invention also provides for the treatment of wallboards and building materials with combinations of fungicides present in synergistic amounts.