The document outlines the objectives and procedures of plastering, including the preparation of surfaces and the application of different types of plaster such as lime, cement, and gypsum plasters. It details the necessary coatings and their respective thicknesses along with precautions to avoid common issues like unevenness and cracking. Additionally, it introduces heat-resistant plaster designed for high-temperature applications.

1. PLASTERING
PRESENTED BY
AGLAIA

2. OBJECTIVES OF PLASTERING
1. To provide an even,smooth,regular,clean and durable finished
surface.
2. To preserve and protect the surfaces from atmospheric influences
4. To cancel the defective workmanship. To cover up the porous
materials and the joints formed in the masonry works.
5. To provide a satisfactory base by applying
whitewashing,painting,distempering.
6. In internal plastering, the basic objective is to protect from dust and
verminnuissance.

3. • Before plastering , the surface should be prepared 
• All masonry joints should be cleaned
• All unevenness should be removed
• Mortar drop and dust is removed with wire brushes
• The surface is washed and kept wet

4. NUMBER OF COAT AND THICKNESS OF
PLASTER
 2 or 3 coat
 Brick work and stone masonry need minimum 2 coat
 Wood or metal need atleast 3 coat
 First coat is known as undercoat or rendering (thickness is
10-15 mm)  seals surface
 Second coat is called floating coat (thickness 6-9 mm)
 Third coat is the finishing coat (thickness is 2-3mm)
 Thickness of the external wall is 20 mm

5.  Lime plaster
 Cement plaster
 Gypsum plaster
 Lime cement plaster
 Heat resistant plaster

6. LIME PLASTER
 Lime plaster is a mixture of calcium hydroxide
and sand (or other inert fillers).
 Carbon dioxide causes the plaster to set by
transforming the calcium hydroxide into calcium
carbonate (limestone).
 Whitewash is based on the same chemistry.
 To make lime plaster, limestone (calcium
carbonate) is heated to
produce quicklime (calcium oxide).

7. CEMENT PLASTER
 Cement plaster  a mixture of sand + portland
cement and water
 Ratio 1:4 - 1:6
 Applied to masonry interiors and exteriors to
achieve a smooth surface.
 Walls constructed with stock bricks are cement
plastered while face brick walls are not plastered.

9.  Various cement-based plasters are also used as
proprietary spray fireproofing products.
 Heavy version of cement plasters are in use for
exterior fireproofing, to protect LPG vessels, pipe
bridges and vessel skirts.
 The advantages of cement plaster were its
 strength,
 hardness,
 quick setting time and
 durability

10. GYPSUM PLASTER
Gypsum plaster or plaster of paris is produced
By heating gypsum to about 150 degree celsius.
Caso4.2h2o+heatcaso40.5h2o+1.5h2o(released as
steam)
Dry plaster powder mixed with water reforms
into gypsum.
 The setting of plaster starts about 10 mins of
mixing & completes after 45 mins
If gypsum is heated about 130 dc anhydrite is
formed.

11. *Anhydrite will reform as gypsum if mixed with
water.
*A large gypsum deposit ay montmartre in
paris led calcined gypsum to be commonly
known as “plaster of paris”.

12. HEAT RESISTANT PLASTER
 Heat resistant plaster is a building material used for
coating walls and chimney.
 Its purpose is to replace conventional gypsum
plasters in cases where the temperature can get
too high .
 Heat resistant plaster should be used in cases
where the temperature exceeds 50 °C.

13. PRECAUTIONS
 Precautions to be taken to avoid unevenness,
efflorescence, cracking 
 Poor workmanship
 Surface not prepared
 Presence of lime
 Too thickness
 Poor curing

14. THANK YOU
Linte
ls
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