A door is simply a movable or hinged barrier which enables ingress into and ingress out of an enclosed area. The created opening either in the exterior wall or the interior wall is usually a door or gate. The primary and important function of a door is to offer protection against intruders, by restricting ingress to the entrance. It also serves as a way to detect when someone or something has been there, for security purposes.
When the door is first installed, the door frame was built around the perimeter of the door opening. This frame is known as the door frame or the door sill. In more modern door constructions, the door frame can be built directly into the wall, as in one piece with an integral door frame unit. Modern doors can have the door sill extends to the inside or the outside perimeter, depending on the type of door.
The door frame is supported by a series of hinges along its perimeter or in the interior. There are generally three types of door hinges, the concealed ones which are located within the frame itself, the surface mounted ones that are fixed onto the frame and the concealed beam hinges which can be hidden within the frame of a door. The door hinges play an important role in the operation of the door. They allow movement in sideways or from side to side but cannot be reversed or moved vertically.
Once the door frame is in place, the door is fastened together using a jamb lock or a frame-and-mortar jamb. The jamb lock is usually made of forged or stamped metal. These days, an increasing number of doors are made using lightweight aluminum which is much cheaper than the forged or stamped metal doors. A door with a jamb of galvanized steel is very heavy and cannot be easily opened without breaking the frame of the door. If you want to install a door with a jamb that uses a galvanized finish, then the door is most likely to be very heavy.
The door unit consists of the hardware that closes the door. The hardware is often installed into a frame of the door or it can be built into the sill of the door. Normally, the door unit consists of two pieces – a head and a body. The head is the front part that you open and the body is the back side that you close. A door with a swinging mechanism is called a patio door. A door with a stationary mechanism is called a skylight.
Before installing a door unit into a door, it is necessary to check whether the door opening is correctly fitted with the jamb. If the opening is not placed flush with the jamb, the door will not close correctly. The door must be able to slide smoothly along the frame and it must also swing freely without any slippage. A door that swings out away from the frame is called a recessed panel door. When installing a door, make sure that the sill is flush with the jamb.