A flush door is a door having all flat surfaces. Flush doors are generally used when aesthetics aren’t the concern, but practicality is. A flush door is completely smooth, usually made of plywood or another laminate put over a frame with a lighter core material. Sometimes a flush door will be hollow. These are generally the least expensive kind of flush doors.
Where to use a flush door
A flush door would be used in an interior function, usually in some part of the house where it isn’t important that the door either be particularly strong or aesthetically pleasing. Basements, closets, in children’s rooms, in unfinished or storage areas, are all places where flush doors are used.
Flush doors made of metal or made of a more substantial material are often used in motels or hotels. A steel door can be a flush door, and heavy steel doors used for fire code applications might be a flush door, for practical reasons.