Siding and Wall cladding is the exterior material which is applied to the walls of a house or building meant to shed water, to protect the walls from the effects of the weather and insulate. Some walls such as solid brickwork and masonry are not covered with siding, but some building can have sided added. Siding may be made of wood, metal, plastic, masonry, or composite materials. It can be attached directly to the building structure or to an intermediate layer of woods called sheeting. An intermediate air/moisture barrier such as house wrap or felt paper can be applied to the sheathing as an air/moisture barrier.