What is the difference between plaster and drywall?
There are several differences. For one, plaster is harder than drywall finishes, which makes it more durable. When mixed with water, plaster has a ‘chemical’ set, whereas joint compound and other drywall finishes tend to have a ‘physical’ set. Since plaster is ‘rock’ out of the ground, when it is mixed with water and made into a putty, a chemical set starts to set it back into rock (Some people have experienced this setting action when they mix plaster of Paris with water). This is one reason why plaster can be applied in very thick layers and used to fill deep holes very quickly. Joint compound is meant to be put on in thin layers and allowed to ‘air dry’. It is sanded between coats and is much softer than plaster is. Since plaster chemically sets, there is no need for sanding, so there is less dust created when working with plaster. Drywall finishing is usually less expensive than plastering, but it also has a tendency to get damaged easier than plastered surfaces.
