A composite board is formed from binding a cover layer to a base layer, wherein the base layer has a composition comprising one or more of the following ingredients: magnesium oxide, recycled magnesium oxide, fibrous chips, wood chips, bamboo chips, chemical additive and water. A method of manufacturing the composite board includes providing the base layer, which includes preparing a semi-arid mixture of the above ingredients, and pouring the mixture through a funnel onto a conveyor belt. The conveyor belt passes the mixture through a series of rollers to remove excess liquid. The layer is cut into panels, which are heat before being sprayed with dried magnesium oxide. A binding agent is applied to one side of the base layer. The cover layer has a bottom surface which is then aligned and bonded to one side of the base layer.