Cement Plaster vs Gypsum Plaster: Which is the Best for you?
September 13, 2024
Introducing
Choosing the right plaster for your walls can significantly affect your project’s overall quality and durability. Cement plaster and gypsum plaster are popular options, each with unique characteristics and benefits. This article will explore the differences between cement plaster and gypsum plaster, helping you decide which one is best suited for your needs.
What is Cement Plaster?
Cement plaster is a mixture composed primarily of Portland cement, fine aggregates (such as sand), and water. This blend creates a paste that can be applied to surfaces to provide a hard, protective coating. The typical ratio of cement to sand is about 1:4, although this can vary depending on the desired thickness and finish.
Read our previous blog article on the best cement for plastering.
Common Applications of Cement Plaster
1. Exterior Walls
Cement plaster is often used on exterior walls due to its robustness and weather resistance. It provides a protective layer that can withstand environmental elements such as rain, wind, and sun.
2. Interior Walls
While commonly used outdoors, cement plaster is also suitable for interior walls in high-traffic areas or locations where durability is essential.
3. Rough Surfaces
It can be applied to rough or uneven surfaces, providing a smooth base for painting or additional finishes.
4. Structural Surfaces
Cement plaster is used to cover structural components such as concrete columns and beams to enhance their appearance and protect them from environmental damage.
Advantages of Cement Plaster
1. Durability
Cement plaster is renowned for its strength and long-lasting nature. It forms a hard surface that resists impact and physical wear, making it ideal for both interior and exterior applications where durability is critical.
2. Strength
The high compressive strength of cement plaster allows it to withstand significant pressure and load. This makes it suitable for heavy-duty applications and environments subjected to stress.
3. Cost-Effectiveness
Generally, cement plaster is more affordable compared to other plaster types. The raw materials—cement and sand—are readily available and inexpensive, contributing to lower material and labor costs.
4. Resistance to Fire
Cement plaster provides excellent fire resistance due to its non-combustible nature. This makes it a safe choice for building fireproof walls and ceilings.
5. Thermal Insulation
Cement plaster has some insulating properties that help regulate indoor temperatures by reducing heat transfer, though it is less effective compared to specialized insulating materials.
6. Moisture Resistance
When properly applied and sealed, cement plaster can offer good resistance to moisture. It protects underlying surfaces from water ingress and can be used in moderate humidity environments.
7. Low Maintenance
Once cured, cement plaster requires minimal maintenance. It is less prone to damage from everyday use compared to other types of plaster, reducing the need for frequent repairs or touch-ups.
Disadvantages of Cement Plaster
1. Drying Time
One of the main drawbacks of cement plaster is its extended drying and curing time. The plaster typically takes several days to set and up to a month to fully cure. This slow process can delay the completion of subsequent stages of construction or renovation.
2. Surface Preparation Requirements
Proper application of cement plaster necessitates thorough surface preparation. This includes cleaning the wall, removing any old paint or debris, and applying a suitable primer to ensure good adhesion. Inadequate preparation can result in poor bonding and reduced durability of the plaster.
What is Gypsum Plaster?
Gypsum plaster, also known as plaster of Paris, is a popular interior plastering. Gypsum plaster is composed primarily of calcium sulfate dihydrate (gypsum) in powder form, which is mixed with water to form a paste. When the mixture is applied to surfaces, it sets into a firm, smooth coating. Unlike cement plaster, gypsum plaster does not require sand, making it a more refined and lightweight material for finishing work.
Common Applications of Gypsum Plastering
1. Interior Walls and Ceilings
Gypsum plaster is predominantly used for internal walls and ceilings. Its smooth finish makes it ideal for areas where aesthetic appeal is important.
2. False Ceilings
Gypsum is frequently used in the construction of false ceilings due to its lightweight and quick-setting nature.
3. Decorative Molding
Gypsum plaster is commonly used in ornamental and decorative moldings in interior spaces, offering precise detailing and a flawless finish.
4. Partition Walls
Gypsum plaster is also used in the construction of partition walls, providing a smooth, paint-ready surface in less time compared to other plaster types.
Advantages of Gypsum Plastering
1. Quick Setting
One of the key benefits of gypsum plaster is its fast setting time. It usually dries within hours, allowing for quicker project completion compared to cement plaster, which may take days to set. This is a significant advantage when time is of the essence, as it enables rapid progress in construction or renovation.
2. Smooth Finish
Gypsum plaster provides an ultra-smooth finish that requires minimal post-application work. Its fine texture eliminates the need for extensive sanding, offering a paint-ready surface that is ideal for interiors where aesthetics matter.
3. Ease of Application
Gypsum plaster is easier to apply than cement plaster. It can be used in thinner layers and spreads more evenly across surfaces. Its lightweight nature makes it less labor-intensive, and it adheres well to surfaces without requiring complex preparation.
4. Crack Resistance
Unlike cement plaster, gypsum plaster tends to shrink less during the drying process, which minimizes the risk of cracks appearing on the finished surface. This enhances the longevity and appearance of the plastered surface.
5. Thermal Insulation
Gypsum plaster provides better thermal insulation compared to cement plaster, which helps regulate room temperatures and improves energy efficiency in buildings.
6. Low Weight
Due to its lighter weight, gypsum plaster is ideal for suspended structures like false ceilings. This reduces the load on the underlying structure, making it safer for use in modern construction.
Disadvantages of Gypsum Plastering
1. Susceptibility to Moisture
One of the major drawbacks of gypsum plaster is its sensitivity to moisture. In high-humidity areas or locations prone to water exposure, gypsum plaster can absorb moisture, leading to deterioration, mold growth, and a weakened surface. For this reason, it is not recommended for exterior walls, bathrooms, or kitchens.
2. Higher Cost Compared to Cement Plaster
While gypsum plaster offers many advantages, it is typically more expensive than cement plaster. The higher cost comes from both the material itself and the specialized labor required for application. This can be a limiting factor for large-scale projects or those with tight budgets.
Cement Plaster vs Gypsum Plaster
Criteria | Cement Plaster | Gypsum Plaster |
Composition | Made from cement, sand, and water. | Made from gypsum powder mixed with water. |
Common Application | Exterior walls, interior walls in high-traffic areas, rough surfaces, and structural components. | Interior walls, ceilings, false ceilings, decorative moldings, partition walls. |
Setting Time | Takes several days to set and up to a month to fully cure. | Quick setting, usually dries within hours. |
Finish | Rougher finish that requires additional work (sanding, painting) for smoothness. | Provides a smooth, fine, and paint-ready surface with minimal finishing required. |
Strength | High compressive strength, durable for heavy-duty use. | Less strong compared to cement plaster, more suitable for interior walls. |
Moisture Resistance | Moderately moisture-resistant when properly sealed but can absorb moisture over time. | Highly susceptible to moisture, not suitable for damp areas like bathrooms or kitchens. |
Crack Resistance | Prone to shrinkage and cracks during the drying process. | Minimal shrinkage, reducing the risk of cracks after drying. |
Thermal Insulation | Provides moderate insulation. | Offers better thermal insulation, helping regulate indoor temperatures. |
Weight | Heavier compared to gypsum plaster. | Lightweight, making it ideal for false ceilings and partitions. |
Fire Resistance | Good fire resistance due to non-combustible nature. | Excellent fire resistance as gypsum contains water molecules that prevent the spread of fire. |
Cost | Generally more affordable due to the low cost of raw materials. | More expensive than cement plaster, including higher material and labor costs. |
Surface Preparation | Requires extensive surface preparation for proper application and bonding. | Requires less surface preparation; easier to apply. |
Durability | Highly durable for both interior and exterior surfaces. | Durable for interior use but unsuitable for areas exposed to moisture. |
Applications in Wet Areas | Suitable for wet or exterior areas with proper sealing. | Not recommended for wet areas due to moisture susceptibility. |
Maintenance | Low maintenance but may require regular checks for cracks. | Low maintenance, minimal risk of cracking over time. |
Cement Plaster vs Gypsum Plaster: Which is Best for You?
To determine the best plaster for your project, consider the following factors:
1. Type of Project
For exterior walls or high-traffic areas where durability is crucial, cement plaster is the better choice. For interior walls where a smooth, aesthetically pleasing finish is desired, gypsum plaster is more suitable.
2. Budget
If you have budget constraints, cement plaster offers a more cost-effective solution. However, if your project allows for a higher budget and prioritizes a quick, smooth finish, gypsum plaster may be worth the extra investment.
3. Desired Finish
For a high-quality paint job and a fine surface, gypsum plaster provides superior results. If a rougher texture or additional finishing work is acceptable, cement plaster can be a viable option.
Conclusion
Both cement plaster and gypsum plaster have their unique advantages and applications. Cement plaster excels in durability and cost-effectiveness, making it suitable for various environments. Gypsum plaster offers a quick, smooth finish ideal for interior projects. By evaluating your project requirements, budget, and desired finish, you can make an informed choice between these two plastering options.
