PLASTER

*PLASTER*

*Basic knowledge of the Plaster :*

Plastering is the process of covering rough surfaces made out of concrete masonry of walls,
columns, ceilings and other building components with thin coat of plaster mortars to form a
smooth durable surface. The coating of plastic material (in mortar) is termed as plaster.

*Objects of plastering*

1. To protect the external surfaces against penetration of rain water and other atmospheric
agencies and should be able to weather uniformly.

2. To give smooth surface in which dust and dirt content lodge

3. To give decorative effect and should also be pleasing in appearance

4. To protect surfaces against varmint. These properties depend upon materials used,
composition of mix, and degree of mechanical bond between the plaster and the backing
surface and workmanship.

*Requirement of good plaster*

1. It should remain adhered during all variations in seasons and other atmospheric
conditions

2. It should posses’ good workability.

3. It should be effectively check penetrations and moisture.

4. It should be hard and durable.

*Cement mortar*

Cement mortar is the best mortar for external plastering work since I is practically non absorbent. One mix proposition (i.e. cement sand) may vary from 1:4 to 1:6 sand used for
plastering should be clean, course and angular. Before mixing water, dry mixing is
thoroughly done. When water is mixed, the mortar should be used within 30 minutes of
mixing, well before initial setting takes place.