The deck of a house is generally a wooden platform built above the ground and connected to the main building. It is generally enclosed by a railing for safety. Access may be from the house through doors and from the ground via a stairway. Residential decks can be constructed over steep areas or rough ground that is otherwise unusable. Decks can also be covered by a canopy or pergola to control sunlight. Deck designs can be found in numerous books, do-it-yourself magazines and web sites, and from the USDA.
Typical construction is either of a post and beam architecture, or a cantilever construction. The post and beam construction relies on posts anchored to piers in the ground. Typically these types of structural decks are engineered and required an experienced construction company that specializes in structural decks. Cantilever decks rely on floor joists that protrude out further than the wall of the house. While this type of construction is common, it raises significant safety issues if the decks are not properly waterproofed and flashed. There have been a growing number deck failures resulting in death and critical injuries. Another key component of decks are code compliant railings. Railings on decks above 30 inches are considered guard rails. Guard rails have a specific building code requirement for both height and structural strength.