Hello, True hard wood flooring would not be ideal. With most floor heating elements they require a mortar set be applied over them to both set the elements, and level the surface. Nailing through this would be not recommended. However, if you are using an engineered floor set( snap-together ) you can have the look of hardwood and warm feet. Take your time and double check your work. once the heating elements are installed, going back is hard work. Good luck!