Basic Carpentry 101: Flats and Jacks

Movie & TV sets are usually made of light weight modular units we call flats. The standard flat has a 1x3 frame with a luan or other thin light weight material skin. Flats are used as walls with openings for doors and windows, etc. The piece above the openings, windows, and doors is called the header. The piece under a window is called the plug. Understanding how to calculate rough openings is a prime skill that requires critical thinking. It is a necessary tool to be able to build sets efficiently. As an IATSE carpenter, you must be well versed with the average style of set construction consisting of walls made up of flats with openings of all sizes. You must be able to use flats outside of traditional applications and apply them to unique situations.