An interior door is a door placed between two interior spaces within a building. Unlike exterior doors, interior doors do not need to be waterproof, heavily insulated or burglar-resistant. Their primary functions are to separate rooms, provide privacy, reduce noise transfer and contribute to the overall look of the interior.
Types of interior doors
Interior doors come in several common types, each with distinct characteristics:
- Panel door — A traditional door with a frame-and-panel construction. The frame consists of stiles (vertical pieces) and rails (horizontal pieces) with panels fitted in between. Panel doors are available in many styles, from classic six-panel designs to modern single-panel versions.
- Flush door — A door with a smooth, flat surface on both sides. It consists of a lightweight core (often honeycomb cardboard or particleboard) sandwiched between two face sheets of plywood, MDF or hardboard. Flush doors are simple, affordable and suit modern interiors.
- Sliding door — A door that slides along a track rather than swinging on hinges. Sliding doors save space in tight rooms and are popular for wardrobes, ensuites and open-plan layouts. They can be wall-mounted or pocket-style, where the door slides into the wall.
Other variations include French doors (double doors with glass panels), barn doors (decorative sliding doors on external hardware) and folding doors.
Dimensions and standards
Standard interior doors in Europe are typically 2015 mm tall and come in widths of 730, 830 or 930 mm. The thickness is usually 38 to 40 mm. Building regulations may require minimum widths for accessibility, particularly in public buildings and adapted housing.
Installation
An interior door is hung in a door frame or lining, which is fixed into the wall opening. The door is attached to the frame with two or three hinges. A latch or lock keeps the door closed. The gap between the frame and the wall is covered with architrave — decorative moulding that provides a clean finish. At the bottom, a small gap of about 10 mm is left for air circulation, unless a threshold strip is fitted.
Related terms
- Door
- Frame
- Panel door
- Threshold
- Hardware
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