Believe it or not, walls in homes are not all created equal! Some homes have plaster walls rather than drywall or sheetrock, and this is true especially of older, vintage homes. Repairing plaster walls is similar to repair drywall but there are some differences, so it's good to understand how to address a damaged plaster wall before attempting such a repair. In many cases it's ever good to employ a plaster wall contractor so that you know the job is done right the first time.
Underneath the plaster coating is a subsurface that is made with what resembles chicken wire and wooden slats. The old plaster surface needs to be cleared away so this subsurface can be reached. With slight damage a plastering contractor may be able to actually mix some new plaster which gets applied over this subsurface in layers. This can be enough to fix small damage. In other cases however, such as if the slats or the wire of the subsurface are bent or damaged, then these need to be addressed and repaired as well.
The wood surface is first secured and then more wire mesh is applied so that the plaster has something to which it will cling and dry. This porous surface of the wire or mesh will allow the plaster to set the way it should. The plaster contractor uses a trowel to add on fresh plaster in layers. As it then dries, it looks just like the rest of the walls and provides a surface that should last for years.
Repairing a damaged plaster wall is just as much art as it is science, as any plastering contractor can tell you. With older homes especially you'll want to employ the services of a professional in order to get the job done right and to preserve the integrity of the home. These things make the small price you pay for his or her services absolutely worth it!