Interior doors are designed and constructed for indoor use, typically in residential and commercial applications. There are many different types of products. Examples include bathroom doors, closet doors, kitchen doors, and laundry room doors; French doors and Dutch doors; accordion doors, bi-fold doors, and pocket doors; mirrored doors, glass doors, privacy doors, wooden doors, and sliding doors; and flush doors and bypass doors. Impact doors for home and office use are also available. Interior doors differ in terms of materials of construction and are available in many different shapes, sizes, and colors. They are not designed to withstand wind, weather, or ultraviolet light (UV), however, and should be installed according to the manufacturer’s recommendations.  

Bathroom doors, closet doors, kitchen doors, and laundry room doors are usually made of wood, plastic, or composite materials. Some products have a medium-density fiberboard (MDF) core that is treated in a thermoforming process. Melamine, a plastic laminate, can be applied as a backing to provide color and a sealed finish. In this way, interior doors like bathroom doors, closet doors, kitchen doors, and laundry room doors can meet the aesthetic requirements of a building and construction project while remaining water-tight and easy-to-clean. Untreated wooden doors are also available, but should be sealed with polyurethane. Multiple coatings may cause the wooden panels to crack, however.

French doors, Dutch doors, accordion doors, bi-fold doors, and pocket doors are common types of interior doors. French doors are single or double doors where most of the door’s area consists of panes of glass surrounded by a frame. One or both doors swing open on metal hinges. Dutch doors have separate top and bottom parts so that one half can remain shut while the other stays open. Accordion doors open by folding back in sections. Unlike other interior doors, they do not swing on hinges. Bi-fold doors are hinged in the middle for opening in a small area. Pocket doors are also designed to save space. When open, they slide into a cavity in the wall.

Suppliers and distributors of mirrored doors may offer mirrored doors, glass doors, privacy doors, wooden doors, sliding doors, flush doors, bypass doors, and impact doors. Mirrored doors are often used to brighten an area. Glass doors are used for decorative purposes and are available with clear, frosted, or colored glass. Privacy doors with frosted glass admit light, but conceal the room’s interior. They are often used as office doors. Typically, wooden doors are made of oak, pine, or cedar. Sliding doors are interior doors that divide two rooms, or an inside room and outdoor patio. Flush doors are usually made of thin sheets of veneer over a core. Bypass doors slide one behind the other. Some impact doors are defined as industrial doors, but others are suitable for indoor use.