|Today interior walls are made of drywall, sometimes called gypsum wallboard or sheetrock. It is a sheet of gypsum (calcium sulfate dihydrate, CaSO4·2H2O) covered on the two sides with a paper facing and paperboard backing. Paper tape is applied over joints and a thin layer of joint compund is applied to conceal the joint. Then the wall is painted.
In 1957 walls were done somewhat differently. The drywall was covered with a thick coat of coarse stucco like plaster and finished with a skim coat of fine plaster. Then the wall was painted. This produced a stronger and more rigid wall. It would be very expensive to duplicate today.