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Plastering Process
Hume Cement
OBJECTIVES
1. To find out properties of plaster preferred by
consumers
2. To identify tools and materials used in
plastering process
3. To point out the method of doing a plastering
work.
4. Summarization
INTRODUCTION
• Plastering process is defined in various definition.
Mostly, it will be considered as a 3-layered
plasters with different methods and plasters for
each layer. However, in this presentation, focus
will be on the plastering process of the first layer,
which is the base layer.
• This presentation will cover about cement plaster,
the most commonly used plasters around the
world.
PROPERTIES OF PLASTER
• Durable - Resistance to moisture penetration. Plaster
serves as a protective layer, which prohibit water
particle from penetrating through the layer, and thus
causing cracks between the layers.
• Workable – Enough water inside mixture of cement
and sand. Water used must be drinkable, free from
chloride and impurities. Workable plaster will able to
cover all irregular surface of the brick wall, increasing
bonding surface area, thus improving bond strength
between wall and plaster.
• *Ratio of mixture:
* Source: http://www.rdso.indianrailways.gov.in/ & http://www.muralist.org/fresco/plastering.html
PROPERTIES OF PLASTER
• Thickness – Suitable range. Too thin, the plaster will have a weak strength,
and higher probability for penetration of water particles. Too thick, will
result in heavier plaster, which could result in falling off plaster before it
reach setting time. Also, thicker plaster will use more cement, and thus is
not economical.
• Adequate/acceptable setting time – Around 1 to 3 hours (initial setting
time). Provides time space for worker to plaster the wall in time, without
compromising on the quality of the plaster. Too soon, the plaster will start
to lose plasticity before worker manage to paste it onto the wall. Too late,
it will consume time, and restrict some follow-up work such as secondary
finishing plaster, or painting job. Also, it might get damaged, if the plaster
situated outside, caused by weather such as sudden rain, storm and other
possible things that could occur.
Situation Ratio (C/A) Thickness (mm)
Internal wall 1:6 10 - 15
External wall 1:4
Drainage 1:3 13
Septic Tank, Reservoir 1:2 19
TOOLS AND MATERIALS USED
TOOLS
1. Plasterer’s Trowel – Tools to scoop the plaster, and apply it
to the wall.
2. The Hawk – To hold or act as small reservoir for the
plaster, while plasterer applies it to the wall.
3. Large bucket – For mixing of plaster to take place
4. Mixer – For mixing purpose. Better if it is an electric
motorized mixer, for a better mixing process.
5. Angle - bending – For a much easier and neater corner
6. Scrapper - To roughen the plastered surface for
preparation of finishing plaster (Sometimes, workers tend
to use their trowel to roughen the plaster applied)
TROWEL
ELECTRIC
MIXER
BUCKET
HAWK
ANGLE BENDING
TOOLS AND MATERIALS USED
MATERIALS
1. Ordinary Portland Cement (OPC)
2. Water
3. Sand
4. Plasticizer (optional)
5. Lime powder
PLASTERING METHOD
Preparation
of tools
Preparation
of plaster
Applying
Plaster
Finish
(Treatment)
PLASTERING METHOD
1. Ensure the wall surface is clean and free from dust, and any loose part of
mortar/plaster from brick laying process. Sprinkle water over the surface to
ensure better sticking of the plaster.
2. Mix appropriate amount and ratio of cement with lime, water and sand. This
is done inside the bucket, with the help of the electric mixer.
3. Using trowel, scoop an amount of plaster which could be hold by the hawk.
4. Then collect half that amount from the hawk, onto the trowel, using a slice
(into the middle) and then a flick of the wrist to scoop it up, with the mortar
mixture facing upwards.
5. Then starting at the bottom of the wall, use nice and smooth strokes with
the trowel and press the mortar onto the wall and try and distribute the
plaster on the trowel evenly over a certain area.
6. Always keep that trowel at a slight angle when laying up (applying) plaster or
the trowel will “stick” in one spot on the wall, by the suction effect that the
wall has when the plaster is drying. (Suction defined as capillary suction)
PLASTERING METHOD
7. Repeat the process with the other area until the wall is
fully covered with the plaster. Wall corners should be the
last to be plastered.
8. Allow the plaster to dry. Increase ventilation if possible,
such as opening windows for air to come in.
9. Scratching should be initiate after some hardness is
achieved within the plasters, usually within few hours, if
another layer of plaster (Usually finishing plaster) is needed.
Source: http://www.neverpaintagain.co.uk/
DEFECT IN PLASTERING
Cracks: Appear on the plastered surface in the form of hair cracks
or wider cracks. Its due to old surface is not properly dressed,
bad workman ship, and due to expansion and shrinkage in plaster
coat during drying.
Efflorescence: Some time soluble salts are present in plaster
making materials or bricks. They appear on the plastered surface
in whitish patches and produced ugly appearance. It may remove
by brushing and washing the surface several times.
Blistering of plastered surface: Small patches swell out beyond
the plastered surface like boils.
Falling out of plaster: Due to excessive thermal variation in
plaster, Inadequate bonding between coats of plaster, and due to
imperfect adhesion of the plaster to the background.
PREVENTION METHOD
• Cracking – Continuous damping of plaster, in order to slow
down any rapid drying, to prevent cracking from happening.
• Blistering – Usually caused by uneven mixing of plaster,
which could be prevented by ensuring a sufficient mixing
between cement and its components to form plaster.
• Falling out of plaster – Thermal variation could be minimized
my the means of water sprinkling method on the surface of
the wall to reduce excessive thermal differences. For the
case of inadequate bonding, it can be prevented by ensuring
the plaster are plastic enough (workable) to stick into the
wall. Imperfect adhesion could be minimized by the act of
good workmanship/carpentership. Ensure to apply enough
pressure to the plaster while plastering, to ensure the plaster
mortar goes into any deep irregular surface, and cover any
holes as much as possible.
CONCLUSION
• Some main properties of plaster that was
highlighted by consumers are the durability,
workability, thickness, and setting time.
• Also, the tools and materials used in plastering
process was listed.
• In addition, the method to do plastering was
explained.
• Finally, the problem for common plastering
process and their suggested solution.
Thank You!

More Related Content

Plastering Process (Cement/Masonry/Finishing Layer)

  • 2. OBJECTIVES 1. To find out properties of plaster preferred by consumers 2. To identify tools and materials used in plastering process 3. To point out the method of doing a plastering work. 4. Summarization
  • 3. INTRODUCTION • Plastering process is defined in various definition. Mostly, it will be considered as a 3-layered plasters with different methods and plasters for each layer. However, in this presentation, focus will be on the plastering process of the first layer, which is the base layer. • This presentation will cover about cement plaster, the most commonly used plasters around the world.
  • 4. PROPERTIES OF PLASTER • Durable - Resistance to moisture penetration. Plaster serves as a protective layer, which prohibit water particle from penetrating through the layer, and thus causing cracks between the layers. • Workable – Enough water inside mixture of cement and sand. Water used must be drinkable, free from chloride and impurities. Workable plaster will able to cover all irregular surface of the brick wall, increasing bonding surface area, thus improving bond strength between wall and plaster. • *Ratio of mixture: * Source: http://www.rdso.indianrailways.gov.in/ & http://www.muralist.org/fresco/plastering.html
  • 5. PROPERTIES OF PLASTER • Thickness – Suitable range. Too thin, the plaster will have a weak strength, and higher probability for penetration of water particles. Too thick, will result in heavier plaster, which could result in falling off plaster before it reach setting time. Also, thicker plaster will use more cement, and thus is not economical. • Adequate/acceptable setting time – Around 1 to 3 hours (initial setting time). Provides time space for worker to plaster the wall in time, without compromising on the quality of the plaster. Too soon, the plaster will start to lose plasticity before worker manage to paste it onto the wall. Too late, it will consume time, and restrict some follow-up work such as secondary finishing plaster, or painting job. Also, it might get damaged, if the plaster situated outside, caused by weather such as sudden rain, storm and other possible things that could occur. Situation Ratio (C/A) Thickness (mm) Internal wall 1:6 10 - 15 External wall 1:4 Drainage 1:3 13 Septic Tank, Reservoir 1:2 19
  • 6. TOOLS AND MATERIALS USED TOOLS 1. Plasterer’s Trowel – Tools to scoop the plaster, and apply it to the wall. 2. The Hawk – To hold or act as small reservoir for the plaster, while plasterer applies it to the wall. 3. Large bucket – For mixing of plaster to take place 4. Mixer – For mixing purpose. Better if it is an electric motorized mixer, for a better mixing process. 5. Angle - bending – For a much easier and neater corner 6. Scrapper - To roughen the plastered surface for preparation of finishing plaster (Sometimes, workers tend to use their trowel to roughen the plaster applied)
  • 8. TOOLS AND MATERIALS USED MATERIALS 1. Ordinary Portland Cement (OPC) 2. Water 3. Sand 4. Plasticizer (optional) 5. Lime powder
  • 9. PLASTERING METHOD Preparation of tools Preparation of plaster Applying Plaster Finish (Treatment)
  • 10. PLASTERING METHOD 1. Ensure the wall surface is clean and free from dust, and any loose part of mortar/plaster from brick laying process. Sprinkle water over the surface to ensure better sticking of the plaster. 2. Mix appropriate amount and ratio of cement with lime, water and sand. This is done inside the bucket, with the help of the electric mixer. 3. Using trowel, scoop an amount of plaster which could be hold by the hawk. 4. Then collect half that amount from the hawk, onto the trowel, using a slice (into the middle) and then a flick of the wrist to scoop it up, with the mortar mixture facing upwards. 5. Then starting at the bottom of the wall, use nice and smooth strokes with the trowel and press the mortar onto the wall and try and distribute the plaster on the trowel evenly over a certain area. 6. Always keep that trowel at a slight angle when laying up (applying) plaster or the trowel will “stick” in one spot on the wall, by the suction effect that the wall has when the plaster is drying. (Suction defined as capillary suction)
  • 11. PLASTERING METHOD 7. Repeat the process with the other area until the wall is fully covered with the plaster. Wall corners should be the last to be plastered. 8. Allow the plaster to dry. Increase ventilation if possible, such as opening windows for air to come in. 9. Scratching should be initiate after some hardness is achieved within the plasters, usually within few hours, if another layer of plaster (Usually finishing plaster) is needed. Source: http://www.neverpaintagain.co.uk/
  • 12. DEFECT IN PLASTERING Cracks: Appear on the plastered surface in the form of hair cracks or wider cracks. Its due to old surface is not properly dressed, bad workman ship, and due to expansion and shrinkage in plaster coat during drying. Efflorescence: Some time soluble salts are present in plaster making materials or bricks. They appear on the plastered surface in whitish patches and produced ugly appearance. It may remove by brushing and washing the surface several times. Blistering of plastered surface: Small patches swell out beyond the plastered surface like boils. Falling out of plaster: Due to excessive thermal variation in plaster, Inadequate bonding between coats of plaster, and due to imperfect adhesion of the plaster to the background.
  • 13. PREVENTION METHOD • Cracking – Continuous damping of plaster, in order to slow down any rapid drying, to prevent cracking from happening. • Blistering – Usually caused by uneven mixing of plaster, which could be prevented by ensuring a sufficient mixing between cement and its components to form plaster. • Falling out of plaster – Thermal variation could be minimized my the means of water sprinkling method on the surface of the wall to reduce excessive thermal differences. For the case of inadequate bonding, it can be prevented by ensuring the plaster are plastic enough (workable) to stick into the wall. Imperfect adhesion could be minimized by the act of good workmanship/carpentership. Ensure to apply enough pressure to the plaster while plastering, to ensure the plaster mortar goes into any deep irregular surface, and cover any holes as much as possible.
  • 14. CONCLUSION • Some main properties of plaster that was highlighted by consumers are the durability, workability, thickness, and setting time. • Also, the tools and materials used in plastering process was listed. • In addition, the method to do plastering was explained. • Finally, the problem for common plastering process and their suggested solution.