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.
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 require 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 of 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. Most U.S. commercial building codes require a 42-inch guardrail on decks, and 36 or 42 inches for a residential code depending on the state. Typical railing assemblies must meet structural strength requirements of 200lbs of load force per foot. In short, decks are complex load bearing structures that most often require structural engineering, plans, and permits.
Residential decks may contain spaces for cooking, dining and seating. Cooking areas ideally should be situated near the patio door while out of the way from general foot traffic. Dining spaces will include patio tables. For a typical 6-person outdoor patio table building an area of 12′ x 16′ (4×5 m) is ideal. If deck space is available, homeowners may choose to include a seating area for outdoor couches and benches.