Building materials are materials used in the construction of buildings, including bricks, concrete, wood, insulation, and roofing. Bricks are a type of masonry material made from clay or shale that is fired in a kiln to create a hard surface. Concrete is a mixture of cement, water, sand and gravel that can be poured into forms to create structural elements like walls and foundations. Wood is a natural material that can be used for framing and other structural components as well as for finishes such as flooring and trim. Insulation helps keep the interior of the building warm by trapping air inside the walls. Roofing materials come in many different types such as asphalt shingles, metal sheets, tile or slate.