The present invention is a decorative mould resistant gypsum wall board for use in constructing walls. The wall board is formed from a non-biodegradable gypsum wall board having opposite sides. The wall board has a water resistant gypsum core sandwiched between two glass fibre reinforced structural matts. A water vapour permeable decorative plastic sheet is bonded to one side of said gypsum wall board by a water vapour permeable adhesive layer. The water vapour permeable sheet may consist of a perforated sheet of decorative vinyl. The finished wall board is decorative, inherently mould resistant and will not act as a vapour barrier.