Type of Plaster
When the construction of a building is complete, certain defects remain which spoil the appearance of the building. Surface finishes are, generally, adopt for the finishing of expose external and internal wall of the building to protect it from weathering agencies and to improve its appearance. Type of plaster are given below :
Types of plaster and their suitability
It is an ideal plaster for external walls. Cement plaster is specially suit for damp conditions such as bath rooms, reservoirs, water tanks, floors, copings, etc. where non absorbent wall surface is essential. It is also use for internal plastering. Guniting plaster is also a cement plaster having 1 cement : 3 sand & is apply under pressure of 25 N/cm2. The constituents, are mix together in a special gun. It is use for lining walls of tunnels, aqueducts, super passages etc.
It is suitable for plastering internal walls of the building. The ratio is 1 lime to 2-3 sand ( or surkhi ) by volume, for internal walls.
It is suitable for temporary sheds and kacha houses etc.
It is suitable for internal as well as external walls of the building. Stucco plastering an excellent marble like finish. It is a decorative plaster and is make with lime or cement mix with fix proportions of sand, crush rock, marble, soapstone, white of eggs, soured curd and fibres with water. It is apply in 3 coats.
Portland cement is generally use for plaster work. It sets under water by the use of cement. Pure cements are difficult to work and as such are not suitable for plastering. To increase the work ability of these mixes, a small amount of lime ( hydraulic ) is add. The lime should not exceed 10 percent by weight. Work ability can also be improve by adding air entraining agents but these may reduce the strength of the mix. For internal plastering and external plastering, the ratio of cement lime plaster is 1:2:9, 1:1:6 for external plasters, below D.P.C.
It is suitable for internal surfaces of high class buildings of historical importance. Moghul plastering is a special type of lime plaster 1 lime : 3 sand : 1 surkhi ( by volume ) to which white of eggs or some fibrous materials are add.
Instead of cement or lime, gypsum ( CaSO4. 2H2O ) is the binding material. They also certain a fix proportion of fine sand. These are use for making architectural fancies and decorative designs on walls and roofs. They set and harden quickly, have great resistance to fire, provide better insulation against heat and sound.