(1) Flooring in a structure. (2) Open structure with flooring erected outside a main building. A deck can have different levels with direct access to the main structure. It is usually constructed of wood having a creative design. In a home, a deck is often used for entertainment purposes and is recreational in nature. In a commercial building a deck is designed to be attractive and add to the ambiance. For example, a restaurant may have a deck where the clientele is served in suitable weather. (3) Roof structural surface where a roof covering system is applied. See also deck roof.