Plastic decking or flooring is made from plastics such as High-density polyethylene (HDPE), Polystyrenne (PS) and Polyethylene terephthalate (PET). Used in place of traditional wood decking, plastic decking is installed over a treated lumber structure that is raised above grade, creating the floor surface of an outdoor living space. Typically adjoined to a structure, such as a home, decks with plastic decking can also be built as a boardwalk or atop of buildings as observation decks.