6 Different Types Of Plastering and Its Purpose

Plastering is an essential technique in construction, offering both functional and aesthetic benefits. From providing a smooth surface for painting to enhancing the structural integrity of buildings, different types of plastering are employed based on the specific needs of a project. This blog explores six distinct types of plastering, highlighting their unique purposes and advantages. Whether for moisture resistance, fire protection, or achieving a decorative finish, understanding the various plastering methods can help in selecting the right approach for any construction or renovation project.

 

 

Additionally, different types of plaster finishes such as textured, stucco, and sand-faced are used for various applications, adding both style and functionality to surfaces.

 

What is Plastering?

 

 

Plastering is the process of applying a smooth or textured coating of plaster to walls, ceilings, or other surfaces in a building. This coating serves several purposes: it protects the underlying structure, provides a durable and aesthetically pleasing finish, and can help to insulate and soundproof the space. Plaster is a mixture of lime, gypsum, cement, and other compounds, applied wet and then hardens as it dries. Plastering is an vital skill in construction and renovation, contributing to the overall quality and durability of the building’s interior surfaces.

 

What is Plastering Process?

The plastering process involves several key steps to achieve a smooth and durable finish on walls or ceilings. First, the surface is cleaned and prepared, ensuring it is clear from dust, dirt, and loose material. Next, a bonding agent is applied to improve adhesion. The plaster mix, typically made from lime, gypsum, or cement, is then prepared. The first coat, called the scratch coat, is applied and scored to provide a key for subsequent layers. After drying, the second coat, called plaster top or brown coat, is applied to level the surface. Finally, a finishing coat is applied and smoothed to the desired texture.

 

Tools Used in Plastering

​​Plastering requires a variety of specialised tools to ensure a smooth and durable finish. Key tools include:

• Hawk: A flat, square board with a manage underneath used to hold plaster while it’s being applied to the wall.
• Trowel: A flat, rectangular tool with a handle, used for spreading and smoothing plaster.
• Float: Used for finishing the surface, ensuring it is even and smooth.
• Plasterer’s Brush: Used to dampen surfaces and clean tools.
• Plastering Rule: A long, straight edge for leveling plaster on walls.
• Mixing Bucket: A large container for mixing plaster.
• Angle Beads: Metal or plastic strips used to reinforce and define corners.
• Screed Board: Used to level the plaster surface, ensuring a consistent thickness.
• Pointing Trowel: A smaller trowel used for detailed work and corners.
• Plastering Stilts: Adjustable stilts used by plasterers to reach higher areas without a ladder.

 

Different Types of Plastering

There are various types of plaster of wall finishes and techniques used in construction projects, such as pebble dash, textured finish, scrapped effect, waterproof plaster, lime plaster, gypsum plaster, rough cast finish, clay plaster, stucco plaster, mud plaster, and sand faced finish.

There are various types of Plastering used in construction projects which includes the following:

 

1. Cement Plastering

 

 

Cement plastering involves using a mixture of a cement sand mortar, and water, sand, to create a strong and durable plaster. This type of plaster is commonly applied in two coats: the base coat (scratch coat) and the finish coat. Cement plaster is known for its excellent strength and resistance to moisture, making it ideal for both interior and exterior surfaces. It’s widely used in construction due to its affordability and durability.

 

2. Gypsum Plastering (Plaster of Paris)

 

 

It uses gypsum, a soft sulfate mineral, mixed with water to create a smooth and fine finish. Gypsum plaster is also called as plaster of paris, formed by mixing gypsum powder with water, and is known for its fire resistance, cleanliness, and strength. It is applied directly to brick, block, or concrete surfaces. Gypsum plaster sets quickly, reducing construction time, and provides a smooth, paint-ready surface. It also has good fire-resistant properties and is lightweight, making it suitable for ceilings and interior walls.

 

3. Mud Plastering

 

 

Mud plastering is one of the oldest forms of plastering, using a mixture of clay, sand, and water. Sometimes, straw or other fibers are added to improve strength and binding properties. This eco-friendly, external plastering is breathable and helps regulate humidity levels, making it suitable for traditional and sustainable buildings. It is often used in rural and low-cost housing.

 

4. Lime Plastering

Lime plastering involves using a mixture of lime, fine sand,, and water.  It has been used for centuries due to its workability and natural antibacterial properties. It allows walls to “breathe,” reducing moisture buildup and improving indoor air quality. Lime plaster is durable and develops a hard, protective finish over time, making it suitable for historic restorations and eco-friendly construction.

 

5. Waterproof Plaster

 

 

Waterproof plaster, often made with a combination of cement and waterproofing compounds, is designed to resist water penetration. This type of plaster is commonly used in areas disclosed to moisture, such as bathrooms, kitchens, and exterior walls. It helps prevent dampness, mold, and water damage, ensuring the longevity of the structure.

 

 

6. Stucco Plaster

Stucco plaster is a decorative finish used on both interior and exterior surfaces. It is made from a mixture of cement, sand, and lime, and sometimes includes acrylic or other additives for enhanced performance. Stucco is applied in multiple layers, creating a textured, durable, and visually appealing surface. It is popular for its flexibility and ability to create various finishes, from smooth to highly textured designs.  

 

Purpose of Plastering

 

 

1. Increase Durability of Masonry

Plastering enhances the durability of masonry by providing a protective top layer of plaster that binds the surface. This layer helps to consolidate the masonry, reduction of the risk of wear and tear over time. By filling in gaps and cracks, plastering prevents moisture ingress and subsequent freeze-thaw damage, which can weaken the structure. This added layer of safety ensures the longevity and stability of the building’s walls.

2. Provide a Plain Surface for Painting Work

One of the primary purposes of plastering is to create a smooth, even surface that is ideal for painting and decorating. Plaster covers up imperfections, such as rough brickwork or uneven surfaces, resulting in a clean and uniform finish. This not only enhances the aesthetic appeal but also makes it easier to apply paint or wallpaper, ensuring a high-quality and visually pleasing result.

3. Provide Protection Against Atmospheric Attack

Plastering acts as a barrier against environmental elements, protecting the underlying brick masonry from atmospheric attack. It shields the building materials from harmful effects of rain, wind, and pollution. By preventing direct exposure to these elements, plaster helps to keep the integrity of the structure and reducing the need for frequent maintenance and repairs.

4. Protect Against Moisture

Moisture can be highly damaging to building materials, leading to issues like mold growth, dampness, and structural deterioration. Plastering provides a moisture-resistant layer on internal walls that prevents water penetration. Specialised waterproof plasters are often used in areas prone to dampness, such as bathrooms and basements, to ensure that walls remain dry and free from moisture-related problems.

5. Provide a Better Aesthetic View

Plastering significantly improves the aesthetic appeal of a building by providing a clean, smooth, and polished surface. It allows for a variety of finishes, from matte to glossy, and can be textured or painted to match the desired style. Plastering can also hide construction flaws and create decorative elements, enhancing the overall visual impact and making spaces look more refined and finished.

 

How To Plaster

 

 

Plastering is an vital skill in construction and home renovation, providing a smooth, durable finish to walls and ceilings. Here’s a step-by-step guide on how to plaster a wall:

Certain steps should be followed, such as checking for undulations, fractures, evenness, letting the plaster set, not applying plaster in multiple layers, and achieving a specific finish.

Preparation:

Cover floors with dustsheets to protect them.

Ensure the wall is clean, dust-free, and any holes or cracks are filled with screen tape.

Apply PVA:

Dilute PVA (Polyvinyl Acetate) with water in a 1:4 ratio and use it to the wall to seal the wall surface and ensure even drying of plaster.

Mix the Plaster:

Following the manufacturer’s instructions, mix plaster with cold water until it reaches a thick, custard-like consistency. Always add plaster to water, not the other way around.

Apply the First Coat:

Using a hawk board and trowel, apply the first two coat full of plaster to the wall, aiming for an even, smooth layer.

Smooth the Surface:

Let the first coat partially dry, then use a trowel to smooth out any imperfections. This might require the next coat or several passes to achieve a flat surface.

Apply the Second Coat:

Once the first thin coat of is dry, apply a second, thinner coat of plaster. Smooth it out with a trowel for a polished finish.

Finishing Touches:

Allow the plaster to fully dry (typically 24 hours), then sand any rough spots lightly for a perfect finish. The wall can now be painted or decorated as desired.

 

Why Plastering Is Necessary

Plastering is essential in construction for several reasons such as:

Surface Protection: 

Plastering provides a first layer of protective barrier for walls and ceilings, safeguarding them from moisture, environmental elements, and mechanical damage. This layer helps extend the lifespan of the building’s structural components by preventing deterioration.

Smooth and Even Surfaces: 

It creates a smooth, even surface ideal for applying paints, wallpapers, and other decorative finishes. This polished surface enhances the aesthetic appeal of interiors and allows for a more professional look.

Structural Integrity: 

Plastering fills in gaps, cracks, and voids, reinforcing the wall and ceiling structures. This contributes to the overall durability and stability of the building.

Fire Resistance: 

Certain types of plaster, such as gypsum plaster, possess fire-resistant properties. These can help slow the spread of fire, providing additional safety to the building and its occupants.

Sound Insulation: 

Plastering can improve sound insulation within a building, reduced noise transmission between rooms and from both external walls and sources. This enhances acoustic comfort in residential and commercial spaces.

Thermal Insulation: 

Depending on the materials used, plastering can offer thermal insulation, assisting to regulate indoor temperatures and improve energy efficiency, contributing to comfortable living conditions.

 

Why there is a requirement for good plastering?

Good plastering is essential for several reasons. It ensures the durability and protection of masonry by providing a robust barrier against moisture, weather elements, and environmental pollutants, preventing structural damage and deterioration. Plastering creates a smooth, even surface, ideal for painting and decorative finishes, enhancing the aesthetic appeal of buildings. It also contributes to thermal and sound insulation, improving energy efficiency and acoustic comfort. Additionally, good plastering covers construction flaws, fills gaps and cracks, and helps maintain hygiene by making surfaces easier to clean and resistant to dust accumulation.

 

Curing of Plaster

Curing is a critical process in plastering, ensuring the strength and durability of the applied plaster. It involves maintaining adequate moisture content in thin layer of the plaster for a certain period to allow for proper hydration and hardening.

 

Methods of Curing:

 

 

• Wet Curing: Involves regularly sprinkling water on the plastered surface to keep it moist for at least 7 days. This method helps prevent the plaster from drying out too quickly, which can lead to cracks.
• Spray Curing: Utilises periodic water spraying to maintain moisture levels. It is particularly effective in hot and dry climates where rapid evaporation can occur.
• Cover Curing: Employs materials like wet burlap or plastic sheets to cover the plaster, preserving its moisture content.
• Chemical Curing: Uses specific chemical compounds that help the plaster set and harden more efficiently.

 

Importance of Curing:

• Strength and Durability: Proper curing significantly enhances the compressive strength of the plaster, making it more durable.
• Crack Prevention: Ensures uniform drying and setting, preventing surface cracks and enhancing structural integrity.
• Smooth Finish: Adequately cured plaster provides a smoother and more visually appealing surface.
• Optimal Adhesion: Ensures the plaster firmly adheres to the substrate, reducing the risk of flaking and peeling.
• Moisture Regulation: Proper curing helps regulate moisture levels within the plaster, preventing issues such as mold growth.

 

Curing Times:

• Gypsum Plaster: Begins setting within 30 minutes to an hour and reaches full hardness in 2-3 days. Maintaining consistent moisture during this period is crucial.
• Cement Plaster: Typically requires a curing period of at least 7 days to ensure full hydration and strength development.

 

Environmental Factors:

• Temperature: High temperature can accelerate the curing process, while lower temperatures can slow it down.
• Humidity: High humidity can protract the drying process, while low humidity can cause the plaster to dry too quickly, leading to cracks.

 

Conclusion

Plastering is a vital process in construction, offering numerous functional and aesthetic benefits. From cement and gypsum to traditional mud and lime, each type of plaster serves a specific purpose, such as enhancing durability, providing fire resistance, or creating decorative finishes. The plastering process, supported by essential tools and proper curing methods, ensures a smooth, protective, and long-lasting surface. 

Good plastering not only improves the structural integrity and lifespan of buildings but also enhances thermal and sound insulation, making interiors more comfortable and visually appealing. Understanding these diverse plastering techniques is crucial for selecting the right approach for any project.