Must mixes ingredients together to make plaster and applies it to walls and ceilings. When applying the plaster, must try to create a smooth or decorative finish on internal walls and ceilings of homes and buildings. Must have knowledge on plaster to repair damaged walls and ceilings. Also need to apply renders and finishes on floors, ceilings and walls, which are other types of protective or shiny layers that make the place applied to have a new look.