Gypsum Vs Cement: Which Is Better For Commercial Plastering?

When it comes to commercial plastering, choosing between gypsum and cement plaster is essential for functionality and appearance. 

Each material offers distinct advantages and disadvantages, impacting the building’s performance, finish, and long-term maintenance. 

This guide compares the two materials in depth, covering aspects like composition, durability, cost, and environmental impact, helping to make an informed decision for your project.

Let’s get straight to the point.

Gypsum and cement plaster are widely used in commercial plastering, each with distinct advantages. 

Gypsum plaster is quick-setting, lightweight, fire-resistant, and offers excellent thermal and sound insulation, making it ideal for non-structural interior uses. 

Cement plaster, on the other hand, is stronger, more durable, moisture-resistant, and suited for exterior or structural applications. 

While gypsum is cost-effective and easy to work with, it is unsuitable for damp areas or exteriors. 

Cement plaster requires more time, water, and labour but provides long-term durability and strength. The choice depends on project needs, environment, and cost considerations.

What Is Gypsum Plaster?

Gypsum plaster is a white cementing substance composed of calcium sulphate and water. It is made by dehydrating gypsum rock and mixing it with additives to improve performance. 

Once applied in its plastic form with water, it hardens through a chemical reaction, providing a smooth surface ideal for interior walls and ceilings. 

Gypsum plaster is especially popular in commercial construction due to its ease of application, energy efficiency, and quick drying time.

Advantages Of Gypsum Plaster

1. Workability: Gypsum plaster spreads easily and evenly, requiring less effort than other plasters.
2. No Shrinkage Cracks: Unlike cement plaster, gypsum plaster doesn’t shrink after application.
3. Quick Setting: It sets within 25 to 30 minutes, allowing painting to begin as soon as 72 hours after application.
4. No Curing Needed: Gypsum plaster requires no water curing, saving time and resources.
5. Lightweight: It reduces the overall dead load on the structure while providing durability.
6. Smooth Finish: The plaster produces an even surface that ensures perfect angles and a professional finish.
7. Fire Resistance: Its natural composition makes it fireproof, adding safety to buildings.
8. Thermal Insulation: Gypsum helps maintain indoor temperatures, leading to lower energy costs.
9. Less Supervision: Gypsum requires fewer quality checks than traditional cement plaster, reducing the need for continuous supervision.
10. Environmentally Friendly: Gypsum is a sustainable material with minimal environmental impact.

Disadvantages Of Gypsum Plaster

1. Not Suitable for Exteriors: Gypsum plaster cannot be used on exterior walls as it retains moisture.
2. Limited Use in Wet Areas: It is not recommended for bathrooms, kitchens, or other constantly damp areas.
3. Higher Initial Cost: Gypsum plaster is more expensive than traditional cement mortar for the same thickness.
4. Short Shelf Life: Gypsum plaster can degrade if not applied within three months, even in dry conditions.

What Is Cement Plaster?

Cement plaster combines Portland cement, sand, and water, commonly used to smooth masonry surfaces. It is suitable for interior and exterior walls and provides a durable, long-lasting finish. 

Cement plaster is ideal for areas requiring extra durability and moisture resistance.

Advantages Of Cement Plaster

1. Strength and Durability: Cement plaster provides a strong, long-lasting surface that can withstand heavy loads.
2. Versatility: It can be applied to both internal and external walls.
3. Moisture Resistance: Cement plaster is less permeable to water, making it suitable for damp environments.

Disadvantages Of Cement Plaster

1. Cracking: Cement plaster is prone to cracks due to its lower tensile and flexural strength.
2. High Water Usage: Cement plaster requires significant water for curing, increasing project costs and time.
3. Expensive and Time-Consuming: The application process is labour-intensive and costly.
4. Waste Generation: Cement plaster produces considerable waste during the application process.

Key Differences Between Gypsum And Cement Plaster

1. Setting Time And Composition

• Gypsum Plaster: Known for its fast setting time of 20-30 minutes, gypsum plaster is ideal for quick projects where time is a priority. It hydrates quickly, transforming from powder to solid within minutes.
• Cement Plaster: Cement plaster sets over a longer period, sometimes requiring days. Its composition of limestone and clay allows for a slower, more controlled hardening process, contributing to its durability.

2. Durability And Strength

• Cement Plaster: Cement plaster is robust and built to last. It can handle heavy loads and provides excellent structural integrity. Its strength makes it suitable for structural applications where durability is critical.
• Gypsum Plaster: While gypsum plaster lacks the physical strength of cement, it excels in non-structural applications. Its smooth finish and lightweight properties make it perfect for interior walls and ceilings.

3. Fire Resistance

• Gypsum Plaster: One of the main advantages of gypsum plaster is its natural fire resistance. When exposed to fire, the water molecules in gypsum release steam, creating a protective barrier.
• Cement Plaster: Cement plaster is also fire-resistant but may weaken after prolonged exposure to high temperatures. Gypsum outperforms cement in fireproofing applications for interiors.

4. Thermal And Acoustic Insulation

• Gypsum Plaster: Gypsum excels in thermal insulation, keeping buildings warm in winter and cool in summer. It also has superior soundproofing qualities, making it ideal for commercial spaces where noise control is essential.
• Cement Plaster: Cement plaster does not provide the same level of insulation or soundproofing as gypsum. Additional insulation may be required to achieve desired thermal and acoustic performance.

5. Availability And Cost

• Gypsum Plaster: Gypsum is more affordable than cement in many regions, making it a cost-effective option for commercial plastering projects. Its widespread availability ensures easy access and reduces supply chain issues.
• Cement Plaster: Cement is often more expensive than gypsum, and costs can vary based on location, type, and quality. However, the long-term durability of cement may justify the higher initial expense in specific projects.

Pest And Rust Resistance

• Gypsum Plaster: Gypsum plaster is resistant to pests like insects and fungi. It is also effective at preventing rust in metal fittings, making it a reliable choice for interiors with electrical installations.
• Cement Plaster: Cement plaster is not immune to mould and mildew. It also does not prevent rust, which can be an issue in environments with high humidity or moisture levels.

Shrinkage And Curing

• Gypsum Plaster: Gypsum plaster has strong tensile and flexural strength, reducing the risk of shrinkage after application. Additionally, it does not require pre- or post-curing, saving time and resources.
• Cement Plaster: Cement plaster is prone to shrinkage due to its weaker tensile strength. It also requires extensive water curing before and after application, which can increase project timelines and water usage.

Density And Ease Of Application

• Gypsum Plaster: Gypsum plaster is less dense than cement, making it lighter and easier to handle during application. This also helps reduce the structure’s weight, benefiting large commercial buildings.
• Cement Plaster: Cement plaster is denser and heavier, which increases the structural load. Applying it is also more labour-intensive and time-consuming, increasing project costs and timelines.

Final Considerations For Choosing Between Gypsum And Cement Plaster

Selecting the right plaster for commercial buildings depends on various factors, including the building’s purpose, location, and specific project needs. Here are some final considerations to keep in mind:

Use Gypsum Plaster When:

• Quick application and fast drying are essential.
• Fire resistance, thermal insulation, and soundproofing are priorities.
• It would help to have a smooth, polished finish for interior walls and ceilings.
• You are working on a project with limited supervision or resources.
• You are looking for an environmentally friendly option.

Use Cement Plaster When:

• Strength and durability are paramount.
• The building will be exposed to heavy loads or extreme weather.
• Moisture resistance is required, such as in bathrooms or exterior walls.
• The project allows for longer curing times and higher water usage.
• You are looking for a material that can be textured or styled in various ways.

Conclusion

Both gypsum and cement plaster offer unique benefits for commercial plastering projects. 

Gypsum plaster is an excellent choice for interior work because it sets quickly, is thermally insulated, soundproofs, and is fire resistant. 

Cement plaster, on the other hand, is valued for its strength, durability, and moisture resistance, making it suitable for structural and exterior applications.

Ultimately, the best material for your project will depend on your specific needs—whether you prioritise quick application and aesthetics or long-term durability and weather resistance. 

Considering time management, cost, and environmental impact, you can choose the most suitable plaster for your commercial building project.

FAQs About Plastering

Which Plastering Material Is More Cost-Effective For Commercial Applications?

Generally, gypsum plaster is more cost-effective than cement plaster in terms of material costs and application efficiency. However, other factors, such as durability and maintenance costs, should also be considered.

Can Gypsum And Cement Plasters Be Used For Exterior Commercial Applications?

Yes, both gypsum and cement plasters can be used for exterior applications, but cement plaster is typically preferred for its superior durability and weather resistance.

How Do I Determine Which Plastering Material Is Best For My Commercial Project?

Consider the building’s location, environmental conditions, desired finish, and budget constraints. Consulting with a professional plastering contractor can help you make an informed decision.

Is One Plastering Material Inherently Better Than The Other For All Commercial Projects?

No, the suitability of gypsum or cement plaster depends on each commercial project’s specific requirements and constraints. Both materials have their unique advantages and applications.

Can Gypsum And Cement Plasters Be Used In A Commercial Project?

Yes, it’s possible to use gypsum and cement plasters in combination, depending on the specific requirements of different areas within the commercial building. This approach allows for optimal performance and cost-effectiveness based on each space’s needs.