Plaster veneer, also referred to as plaster skim in some countries, is a method of finishing interior walls. The process of applying a plaster veneer begins with specially formulated gypsum boards, which are nailed onto wall studs to create a flat interior surface. A thin coating of plaster can then be applied to the gypsum, resulting in a smooth, seamless finish. Tints can be mixed into the plaster prior to its application if some type of color is desired, though it is also possible to apply paint or wallpaper at any point after the material has dried. Plaster veneer is typically more expensive than drywall, though it offers many of the benefits of a traditional lath and plaster finish without the associated costs.
Prior to about the 1950s, the lath and plaster method was the most common technique used to create interior wall surfaces in the western world. This was a very labor intensive method that involved nailing horizontally orientated lathing strips to interior wall studs. About 13 millimeters (0.5 inches) of plaster was then applied to the lathing in two coats. The first coat of plaster would be pressed through the gaps in the lath material, and then the second coat could provide a smooth, durable surface. Drywall began to replace lath and plaster in the 1950s, though plaster veneer was also introduced as a combination method.
The first plaster veneer techniques were very similar to the old lath and plaster method. Instead of wood lath, thin strips of gypsum board were used to anchor the plaster in place. Later developments led to larger sheets of this gypsum board, which were essentially just drywall with a different exterior layer. These specially designed gypsum boards are coated in two paper layers, one of which absorbs moisture and another that resists it. This allows plaster to bond with the boards, while the internal gypsum core remains protected from moisture damage.
Plaster veneer is applied similarly to the old lath and plaster method, though far less material is used. In some cases the plaster layer is only about 3 millimeters (0.1 inches) thick, though different applications can vary. The walls typically need to cure for several days to over a week, depending on the thickness of the application. After they have cured, it is then possible to apply paint, wallpaper or other finishing touches. It is also possible to mix tints in with the plaster prior to application, which can result in colored walls that do not require paint or any other type of finishing.