screed application

In the realm of construction, achieving a level and durable surface is paramount. Whether it’s for a residential space, a commercial establishment, or an industrial facility, the quality of the flooring sets the foundation for everything else. This is where various types of screed application comes into play. In this blog post, we’ll delve into the intricacies of screed application, exploring what it is, why it’s important, how it’s done, and addressing common questions that often arise.

What is Screed Application?

Screed application involves the process of laying down a thin layer of concrete mixture over a full concrete base or floor. This layer, known as screed, acts as an intermediate surface between the structural concrete slab and the final flooring material. It’s typically composed of cement, sand, and water, with variations in composition and thickness depending on the specific requirements of the project.

Why is Screed Application Important?

The importance of proper screed application cannot be overstated. Firstly, it enhances the structural integrity of the floor, providing support and stability for the final flooring material. Additionally, it ensures a level surface, which is crucial for the installation of tiles, hardwood, or other flooring finishes. A well-executed flooring screed and application can prevent issues such as unevenness, cracking, and premature wear of the floor.

How is Screed Application Done?

Screed application involves several steps to ensure proper bonding, leveling, and curing of the material:

  1. Surface Preparation: Thoroughly clean the surface to remove any debris, dust, or contaminants. Prime the surface to improve adhesion and reduce the risk of delamination.
  2. Moisture Testing: Test the substrate for moisture content, especially for applications over concrete substrates. Excessive moisture can lead to adhesion issues and other problems.
  3. Installing Edge Insulation: Install edge insulation to prevent thermal bridging and reduce the risk of screed shrinkage at the perimeter.
  4. Mixing the Screed: Prepare the screed mixture according to the manufacturer’s instructions, ensuring the correct ratio of cement, sand, and water.
  5. Pouring and Spreading: Pour the mixed screed onto the prepared surface and spread it evenly using a screeding tool or straightedge.
  6. Screeding and Leveling: Level the screed using a screeding board or power screed to achieve the desired thickness and levelness.
  7. Curing the Screed: Allow the screed to cure properly to achieve the desired strength and durability. Use appropriate curing methods such as wet curing, membrane curing, or curing compounds.

What is Underfloor Heating?

screed application

Underfloor heating, also known as radiant floor heating, involves the installation of heating elements beneath the floor surface. These heating elements can either be electric resistance cables or water-based pipes, which emit heat upwards, evenly warming the entire room from the floor up. This radiant heat provides a cozy and comfortable environment, eliminating cold spots and drafts often experienced with conventional heating systems.

Benefits of Underfloor Heating:

  1. Uniform Heating: Unlike traditional radiators or forced-air systems, underfloor heating distributes heat evenly throughout the room, eliminating cold spots and ensuring consistent warmth from floor to ceiling.
  2. Energy Efficiency: Underfloor heating operates at lower temperatures compared to traditional heating systems, resulting in reduced energy consumption and lower utility bills. Additionally, radiant heat retains warmth more efficiently, providing long-lasting comfort even after the system is turned off.
  3. Space-saving Design: Underfloor heating systems are installed beneath the floor, eliminating the need for bulky radiators or ductwork. This frees up valuable wall space and allows for more flexible room layouts and interior design options.
  4. Improved Indoor Air Quality: Unlike forced-air systems, underfloor heating does not circulate dust, allergens, or airborne pollutants, resulting in cleaner and healthier indoor air quality.

Installation Process:

  1. Subfloor Preparation: The first step in installing underfloor heating is preparing the subfloor. This involves ensuring a flat and stable surface, free from any debris or imperfections that could affect the heat distribution.
  2. Installation of Heating Elements: Depending on the type of underfloor heating system chosen (electric or water-based), heating elements are installed either directly onto the subfloor or within specially designed mats or panels.
  3. Flooring Installation: Once the heating elements are in place, the flooring material is installed on top. Underfloor heating is compatible with a wide range of flooring materials, including tile, stone, laminate, and engineered wood.
  4. Thermostat Installation and Programming: A thermostat is installed to control the underfloor heating system. Modern thermostats offer programmable features, allowing users to set heating schedules based on their preferences and lifestyle.

What is Unbonded Screed?

screed application

Unbonded screed, also known as floating screed, is a type of floor screed that is applied on top of a separating layer, rather than directly onto the substrate. This separating layer, typically a polyethylene membrane or foam insulation, prevents the bottom screed layer from bonding to the substrate, allowing it to move independently. Unbonded screed is commonly used in both residential and commercial construction projects, offering flexibility and performance in various flooring applications.

Benefits of Unbonded Screed:

  1. Reduced Risk of Cracking: Because unbonded screed is not directly bonded to the substrate, it has greater flexibility and is less prone to cracking due to shrinkage or movement in the substrate.
  2. Improved Thermal and Acoustic Performance: The separating layer in unbonded screed acts as an additional thermal and acoustic barrier, enhancing the overall performance of the floor assembly.
  3. Versatility: Unbonded screed can be used in various flooring applications, including residential homes, commercial buildings, and industrial facilities. It is suitable for both new construction and renovation projects.

What is Cement Screed?

screed application

Cement screed is a mixture of cement, sand, and water applied onto a concrete subfloor or base to create a smooth and level surface. It serves as an intermediate layer between the structural, concrete floor or slab and the final flooring material, providing support, stability, and a uniform surface for installation. Cement screed is commonly used in both residential and commercial construction projects due to its versatility and durability.

Composition of Cement Screed:

Cement screed typically consists of the following ingredients:

  1. Cement: Portland cement is commonly used in cement screed due to its binding properties and ability to harden when mixed with water.
  2. Sand: Fine aggregates such as sand are added to the mixture to improve workability and reduce shrinkage.
  3. Water: Water is added to the cement and sand mixture to initiate the hydration process, allowing the mixture to bond and harden into a solid screed.

Bonded Screed

screed application

Bonded screed is a reliable and versatile solution for achieving a sturdy and level surface in various construction projects. With its strong bond, smooth finish, and compatibility with different flooring materials, bonded screed flooring proves to be an indispensable component in creating durable and long-lasting floors.

Installation Process:

  1. Substrate Preparation: The substrate, which could be concrete or an existing floor surface, must be clean, dry, and free from any contaminants. Any irregularities or voids in the substrate should be filled or leveled to ensure a smooth surface for the screed.
  2. Priming: Prior to screed application, the substrate is primed with a suitable bonding agent to enhance adhesion between the screed and the substrate. This step is essential for ensuring a strong and durable bond.
  3. Mixing and Application of Screed: The screed mixture, consisting of cement, sand, and water, is prepared according to the manufacturer’s instructions. The mixed screed is then applied onto the primed substrate using screeding tools or straightedges, ensuring a uniform thickness and level surface.
  4. Finishing and Curing: Once the screed is applied, it is leveled and smoothed using a float or trowel to achieve a smooth surface finish. The screed should then be allowed to cure properly, typically for several days, before any further flooring materials are installed.

Benefits of Bonded Screed:

  1. Strong Bond: Bonded screed forms a strong and durable bond with the substrate, providing stability and longevity to the flooring system.
  2. Smooth Surface: Bonded screed creates a smooth and level surface, eliminating unevenness and imperfections in the substrate.
  3. Compatibility with Underfloor Heating: Bonded screed is compatible with underfloor heating systems, providing an efficient and even distribution of heat throughout the space.
  4. Versatility: Bonded screed can be used with a wide range of flooring materials, including tiles, wood, vinyl, and carpet, making it suitable for various residential, commercial, and industrial applications.

Mastering screed application is a vital skill for anyone involved in construction or renovation projects. By understanding the importance of proper preparation, execution, and curing of screed board, contractors can achieve optimal results and ensure the long-term performance of the floor. With the right knowledge and techniques, screed application becomes a seamless process, laying the groundwork for a sturdy and flawless flooring surface.



  1. How long does screed take to dry?
    • The drying time for screed can vary depending on factors such as thickness, ambient temperature, and humidity. In general, screed may take several days to weeks to dry completely.
  2. Can you walk on screed after it’s been applied?
    • It’s best to avoid walking on screed until it has fully cured to prevent damage or indentation. Follow the manufacturer’s recommendations for curing time before allowing foot traffic.
  3. What is the difference between screed and concrete?
    • While both screed and concrete contain similar ingredients, screed is typically thinner and applied as a finishing layer over a substrate. Concrete, on the other hand, is used for structural purposes and may contain additional aggregates for strength.
  4. Can screed be used outdoors?
    • Yes, screed can be used outdoors, but it’s essential to select a suitable type of screed that can withstand exposure to the elements and provide adequate drainage.
  5. How thick should screed be?
    • The thickness of screed depends on factors such as the type of substrate, intended use, and the final flooring material. In general, screed thickness can range from 25mm to 75mm or more, depending on the specific requirements of the project.