Difference Between Anhydrite Screed and Cement Screed.

When it comes to flooring, one of the key decisions is choosing the right type of screed. “Anhydrite screed vs. Cement Screed” is a standard comparison. This is because both materials have unique properties and applications.

Whether you’re a contractor or an architect, you should understand the differences between anhydrite screed and cement screed. This knowledge helps you make an informed decision. Adapt screed to your individual needs. It is unique to your project.

Let us give you a quick preview:

Anhydrite Screed

Anhydrite Screed levels itself and dries faster. It is often favored in large-scale projects where time management is crucial. It offers a smoother finish and is less prone to cracking. But, people recognize cement screed for its strength and durability. This makes it ideal for heavy loads or high-foot traffic areas. Anhydrite screed can cover large areas of up to 2000 square meters without joints.

Cement Screed

Cement screed is versatile and works in both internal and external environments. It is ideal for creating a smooth, level surface. You can apply it in residential, commercial, and industrial settings. Use a minimum thickness of 25mm for bonded applications and 50mm for unbonded ones. It offers durability and strength. Choose cement screed for reliable flooring projects.

You can select the screed that best meets your needs by weighing both screeds’ pros and cons. The right type of screed selection is crucial. Pair it with the appropriate project. This ensures a solid and long-lasting foundation.

Let’s get into detail on Anhydrite Screed vs Cement Screed.

What is Anhydrite Screed?

Anhydrite screed is a flowing screed made from a mixture of anhydrite (a type of calcium sulfate) and water. The calcium sulfate binder is a by-product of various industrial processes. One of its main advantages is that it requires less water during installation. This compares directly to traditional screeds. It simplifies the mixing process.

Anhydrite screed offers superior thermal conductivity, making it an excellent choice for underfloor heating systems. It allows for more efficient heat distribution and energy savings. However, it has longer drying times, sometimes requiring weeks to cure fully. It is also sensitive to moisture, compromising its strength and stability if not properly managed.

What is Cement Screed?

Cement Screed is a mixture of cement, sand, and water. This traditional screed material is known for its versatility, strength, and durability. It is suitable for many construction projects, and valuable in high-traffic areas like commercial buildings and public spaces. It is also used in outdoor applications like driveways and patios.

Cement screed sets and dries faster than anhydrite screed, benefiting projects with tight timelines. However, more water is required during the mixing process. This can complicate the installation and affect the final strength if not correctly proportioned. Additionally, cement screed has limited thermal conductivity. This makes it less efficient for underfloor heating systems than anhydrite.

Pros and Cons: Anhydrite Screed vs Cement Screed

There is no better way to settle the debate of Anhydrite Screed vs. Cement Screed than a typical pros and cons list. This might feel like Ross and Rachel from F.R.I.E.N.D.S to you, but surely the list works!

Here are several pros and cons of both materials: anhydrite and cement screed. Consider them to decide which is best suited to your project.

Anhydrite Screed:

Pros:

Here are some of the pros of anhydrite screed:

• Rapid Drying Times: Under optimal conditions, anhydrite screed can be walkable within 24 hours, allowing for floor finishes in as little as 48 hours.
• Thinner Sections Possible: Typically applied at 30-40mm thickness, with the potential for even thinner applications down to 20mm.
• Underfloor Heating Compatibility: Excellent thermal conductivity makes it ideal for underfloor heating systems, maximizing efficiency.
• Lightweight: Weighs approximately 50 kg per square meter, which can be beneficial for specific structural requirements.
• Sustainability: Boasts a low CO2 emission profile, presenting an environmentally friendly option.
• Long-Term Performance: Maintains hardness, strength, and integrity over time without a tendency to crack.

Cons:

Every pro has a con. Here are a few cons of anhydrite screed:

• Repair Complexity: Difficult to patch or replace, and achieving an exact color match can be challenging.
• Noise Insulation: Provides minimal noise insulation, though additional materials can improve this.
• Chemical Resistance: Offers moderate chemical resistance and can be susceptible to acid damage if not protected with epoxy.
• Precise Installation Requirements: Requires adherence to strict guidelines for storage, mixing, pumping, joints, and curing, which may complicate the installation process.

Cement Screed:

Pros:

Here are a few benefits of cement screed for you:

• Cost-Effective: Generally less expensive than anhydrite screed, costing around £30-50 per m² for materials and professional installation.
• Durability: Highly durable and can develop only minor cracks over time with proper installation and maintenance.
• Ease of Repair: Repairing and bonding new cement to old screed is more effortless, simplifying the color-matching process.
• Noise Insulation: Excellent for impact and airborne noise insulation, especially when combined with acoustic mats or membranes.
• Flexural Strength: Possesses a higher flexural strength of 6-9 N/mm² depending on mix designs, enhancing durability and resilience.
• Chemical Resistance: Due to its alkaline properties, it is Good at resisting dilute acids, oils, and many chemicals.

Cons:

There are a few limitations to Cement Screed. Here are some of them:

• Long Drying Times: It takes 7-14 days before it is suitable for foot traffic and 21-90 days to fully cure before applying finishes.
• Heavier Weight: Weighs roughly 75 kg per square meter, which could be a consideration for certain structural limits.
• Sustainability: Higher carbon footprint than anhydrite screed due to more emissions-intensive production processes.
• Higher Minimum Thickness: Usually applied at a minimum thickness of 40mm on ground floors and 50mm on upper floors, with typical usage at 65mm or more.

We hope this clarifies your basic confusion. Now, let’s move on to our main topic: Anhydrite Screed vs. Cement Screed.

What is the difference between Anhydrite Screed and Cement Screed?

When comparing anhydrite screed vs. cement screed, several factors must be considered, including drying times, thickness, underfloor heating compatibility, etc. The table below provides a detailed comparison of the two materials across different parameters.

Parameter	Anhydrite Screed	Cement Screed
Drying Times	Walkable in 24 hours. Floor finishes in 48 hours if conditions are adequate.	It takes 7-14 days before foot traffic and 21-90 days to cure for finishes fully.
Thickness	Typically 30-40 mm thick. Thinner sections down to 20mm possible.	Minimum 40mm on ground floors, 50mm on upper floors. Often used at 65mm+.
Underfloor Heating	Excellent thermal conductivity and efficiency.	Good thermal conductivity, though slightly less efficient than anhydrite.
Weight	Approximately 50 kg per square meter.	Roughly 75 kg per square meter.
Cost (2024)	£50-70+ per m² for supply and installation.	£30-50 per m² for materials and professional installation.
Sustainability	Low CO2 emissions, good environmental profile.	Higher carbon footprint, emissions-intensive production.
Performance Over Time	Maintains hardness, strength, and integrity long-term. Not prone to cracking.	It is durable but may develop minor cracks over time.
Repairability	Difficult to patch or replace; requires precise color matching.	It is more accessible to repair and bond new cement to old screed, and it is more straightforward color matching.
Noise Insulation	Minimal insulation on its own; dense aggregates can help.	Excellent impact and airborne noise insulation, especially with acoustic mats/membranes.
Flexural Strength	Tensile strength of 5-7 N/mm².	Higher flexural strength of 6-9 N/mm² depending on mix designs.
Chemical Resistance	Moderate chemical resistance, susceptible to acid damage without epoxy.	Stands up well to dilute acids, oils, and many chemicals due to alkaline properties.
Installation	Requires strict storage, mixing, pumping, joints, and curing guidelines.	It is more forgiving but requires careful base prep, reinforcement, and curing practices.

Why call us?

Choosing between an anhydrite and cement screed depends on your specific project requirements. The London Screed Company Ltd. provides expert services to help you make the best choice.

Anhydrite screed is ideal for underfloor heating systems and sustainable projects. Similarly, cement screed is suitable for fast-track construction, high-traffic areas, and outdoor applications; consider the trade-offs between drying times, environmental impact, and cost to make the best decision for your project.

Here at The London Screed Company Ltd., we assist you in choosing and applying the suitable screed for your construction project. We focus on sustainability and efficiency. We prioritize sustainability and efficiency. Our use of environmentally friendly materials and methods demonstrates our commitment to reducing the environmental impact of our operations. Whether it’s the superior thermal conductivity of our anhydrite screeds or the rapid drying times of our cement screeds, we offer solutions that meet and exceed industry standards. When considering anhydrite screed vs cement screed, our offerings are designed to provide the best of both worlds!