Plastering work is a process of covering the rough surfaces or unfinished surfaces like walls, ceilings, column and other building components with thin coat of cement mortar or other material to form a smooth and finished surface and gives an aesthetic appearance. It increases the durability of surface.

Purpose of plastering :
1. It provides flat, smooth and even surface.
2. It makes masonry or AAC block wall more durable.
3. It protects inner surface from atmospheric conditions.
4. It can resist the cracks which may develop in wall.
5. It provides suitable surface for painting or any other aspect.
6. It prevents the penetration of water.
7. It provides hard surface which do not scratched by the sharp things.

Classification of plaster

It may be classified based on three parameters which are given below.
1. Based on material
2. Based on Finishes
3. Based on coat

1. Based on material :
  • Lime plaster : It involves the sand and lime as a main material. Generally it is non-hydraulic hydrated lime which is also known as slaked lime. But it is not that hard compare to cement plaster.
  • Gypsum plaster : It consists gypsum as a main material instead of cement. It is available in ready to use format and does not need sand. It is used only on internal walls and ceilings due to it can not resist the water and deteriorate from water Hence it can not be used in wet areas like kitchen, wash area, toilet, balcony etc. It does not require curing. It can be applied on amooth and rough surfaces.
  • Cement plaster : It consists cement and sand as a main material and mixed with water to make mortar. It is suitable for both inside and outside plaster. It gives hard and tough surface which is also can resist the water. It makes wall more stronger.
  • Clay plaster : It consists clay and sand as a main material and mixed with water to make mixture. Sometimes it mixed with the plant fibers to increase tensile strength. 
2. Based on finishes :
  • Smooth plaster finish : As per its name, It gives smooth surface finish to object. Mortar is used for finish which is made by cement and fine sand. Mortar is applied with the help of wooden float. Usually this kind of plaster is used to finish internal walls.
  • Rough plaster finish : As per its name, It gives rough surface finish to object. It uses mortar for finishing the object which is made by cement and sand. some times it mixed with small size aggregate like grit to get more roughness and strength. Usually this type of plaster is used to finish outside walls.
  • Sand face plaster finish : It is actually a layer of cement-sand mortar which is used to coat the surface.Basically It used to plaster outside walls It gives the sand finishes surface. It adds decorative appearance to building. To some extent it provides sound and thermal insulation.
  • Textured plaster finish : Textured finish is obtained from the stucco plastering. Textured plaster finish can be created with different tools on the final coat. This type of finish possesses all the advantages of rough cast finish.
  • Pebble dash plaster finish : Pebble dash plaster is similar to roughcast plaster. It is a finish in which small pebbles or crushed stones of suitable size are used after first coat of plastering. Pebble aggregates are dashed on to the coated surface and press on them by using wooden float into the plastered surface and press on them by using wooden float into the plastered surface slowly. After pressing cement slurry is cleared to give a look of only stones. Many times groves or pattern are created to give a better look. After hardening they provide an aesthetic look to the structure.
3. Based on coat :
  • Single coat plaster : The first coat applied of thickness around 10 mm, then it is scratched by wire comb to obtain rough surface. This plaster is known as single coat plaster. It is used in bathroom, toilet and kitchen where tile cladding is necessary. It is also used in external plaster.
  • Double coat plaster : The second coat of plaster is final coat with lean mortar. It is also a 10 mm thick. It is also known as finish coat. 


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