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There are two most common materials used in plastering - gypsum and lime plasters. Lime plaster was widely used in most plasterworks during the 19th century. Lime plaster is typically made out of lime, fiber, aggregate and water. Lime is usually derived from oyster shells and lime stones while hog or cattle hair is the fiber component used in the plaster mix.

There are two most common materials used in plastering - gypsum and lime plasters. Lime plaster was widely used in most plasterworks during the 19th century. Lime plaster is typically made out of lime, fiber, aggregate and water. Lime is usually derived from oyster shells and lime stones while hog or cattle hair is the fiber component used in the plaster mix.

Changes in the construction industry have led to the development of gypsum plaster as an alternative to lime plaster. Eventually, gypsum and lime plasters were also combined and used as a composite plastering material although gypsum slowly became the preferred plastering material for most tradesmen.

When constructing a house or building, the traditional practice of plasterers is to mix quick lime and water in order to hydrate the powder compound. As soon as the water is absorbed by the lime, heat is released. This is an indication that the chemical reaction has occurred and that the mixing process is complete. The resulting putty is then used a plastering material.

Fiber material is usually added to the lime plaster in order to get a coarse plaster and this type of plastering material is usually applied in two layers on the masonry in order to achieve the desired thickness. In most cases, plasterers apply three coats of the lime plaster. The first two layers are of the coarse material is known as the brown and scratch coat while the final coat serves as the setting stuff.

This final layer of the plasterwork uses a plaster mix that has a higher amount of lime putty and lesser amount of aggregate. Further, the plaster mix does not contain any fiber in order to attain a fine and smooth finish.

The first two plaster coats must attain at least 3/8 inch of thickness each while the finishing coat must be at least 1/8 inch thick. Additives can be combined with the final plaster coat in order to create the desired kind of finish. The types of additives used include gypsum and whitish sand. Plasterers normally add minimal amount of gypsum in order to reduce the setting time of the plastering material.

Gypsum became a popular plastering material during the 1900s. One of the main characteristics of gypsum is that it immediately begins the curing process the moment it is mixed with water. Once water is mixed with the plastering material, the setting process begins in just a few minutes and the drying process of this plastering material is completed in 2 weeks or so. Gypsum is preferred to lime mainly because it eliminates the need for a fiber component when making the plastering material. Further, gypsum is admittedly the more rigid plastering material between the two powder compounds.

Notwithstanding all of these distinct advantages of the plastering material, gypsum is prone to damage when exposed to moisture and damp conditions. Thus, lime plaster is more appropriate as plaster coating for masonry and when doing external plastering jobs.