What Are Floor Screed and Self-Levelling Screed? Where and How Are They Used?

What Are Floor Screed and Self-Levelling Screed? Where and How Are They Used?

A building's durability, as much as its aesthetics, starts from the floor. A smooth, sound and long-lasting floor is of vital importance for both structural safety and comfort of use. This is where “screed applications” come into play. Self-levelling screeds in particular are among the indispensable materials of modern buildings. In this article we will examine in full detail what floor screed is, how self-levelling screeds differ, their areas of use and their application techniques.

What Is Floor Screed?

Floor screed is a cement-based building material applied over a concrete surface that corrects irregularities in the floor and prepares a smooth substrate for the final covering (tiles, parquet, vinyl, etc.).

Before moving on to the final layer of the building, it ensures that the surface is smooth and even. This both extends the life of the covering material and distributes the load on the floor evenly.

Floor screeds can be of different types depending on the admixtures they contain:

• Conventional Screeds: Traditional screeds prepared from a mix of sand, cement and water that require levelling with a trowel.
• Ready-Mixed Screeds: Modern formulations pre-mixed at the factory that can be applied easily by adding water.
• Self-Levelling Screeds: The most advanced type of screed. Thanks to its fluid structure, it spreads by itself over the surface it is poured onto and provides perfect levelling.

This last group stands out in the construction industry as a time-saving solution offering high precision with minimal human error.

What Is Self-Levelling Screed?

A self-levelling screed, as the name suggests, “levels itself”. In other words, when poured onto the surface it spreads under the effect of gravity and forms a flat surface without the need for trowel levelling.

These screeds consist of high-quality cement, polymer admixtures and special fillers. This formulation provides fluidity, perfect spreading over the surface and high adhesion (bond strength).

Advantages:

• Creates an even and smooth surface.
• Applied in a much shorter time than conventional screeds.
• Dries quickly; the covering can be laid within a short time.
• Minimises the risk of cracking, dusting or blistering on the surface.
• Works perfectly with underfloor heating systems.

For example, KraftBau Self-Levelling Screed, with its high fluidity, fast drying and high strength, has a wide range of uses from industrial buildings to residential projects.

Where Is It Used?

Self-levelling screeds are preferred in all areas that require high surface quality and flatness.

The main areas of use are:

• Residential floors: Provides the ideal base layer before laying parquet or tiles.
• Offices and commercial areas: Smooth floors resistant to heavy foot traffic are achieved.
• Institutions such as hospitals, schools and shopping centres: Offers advantages in terms of hygiene, flatness and long service life.
• Industrial facilities: Creates a perfect base before epoxy, polyurethane or vinyl coatings.
• Underfloor heating systems: Thanks to its fluid structure, it spreads uniformly around the pipes and balances heat distribution.

Self-levelling screeds also offer great convenience in renovation projects where old floors need to be renewed or surface defects corrected.

Application Steps

A self-levelling screed application performs to a high standard when carried out with correct surface preparation and mixing ratios.

1. Surface Preparation: The floor must be dry, clean and dust-free. Oil, paint residue or loose parts must be cleaned off.
2. Primer Application: A suitable primer (for example KraftBau Primer 100) is applied to balance the absorbency of the surface. This ensures that the screed bonds perfectly to the surface.
3. Preparing the Mix: The self-levelling powder is mixed with water in accordance with the manufacturer's instructions. The mix must be fluid but homogeneous.
4. Application: The mix is poured onto the surface and allowed to spread by itself. Uniform distribution can be assisted by guiding it lightly with a trowel or rubber squeegee.
5. Removing Air Bubbles: Air bubbles are eliminated by passing a “spiked roller” over the surface.
6. Drying Process: Once the application is complete, the covering can be laid on the surface within 4–24 hours depending on the ambient temperature.

During application, the ambient temperature should generally be between 5–30 °C. Direct sunlight, wind or excessively hot environments should be avoided as they can disrupt the drying balance.

Differences Between Self-Levelling Screed and Conventional Screed

Property	Conventional Screed	Self-Levelling Screed
Application Method	Levelled with a trowel	Levels itself
Application Speed	Slow	Fast
Surface Flatness	Average	Excellent
Drying Time	3–7 days	1–2 days
Underfloor Heating Compatibility	Limited	High
Area of Use	General	Professional / decorative floors

Professional Tip: The Right Product, the Right Performance

Every project has different floor conditions and load requirements. For this reason, screed selection should be made according to the intended use of the environment.

• For indoor residential applications, self-levelling screeds with high fluidity that can be applied at low thickness are ideal.
• For industrial areas, specially formulated products offering high compressive strength should be preferred.
• For heated floors, flexible, crack-resistant screeds should be used.

KraftBau's professional product range offers formulations suited to all of these requirements. Moreover, thanks to their ready-mixed structure, they minimise application errors and save time.

Conclusion: A Perfect Base for Perfect Floors

Floor screed is the unseen but most important layer of a building. Whatever covering is laid on top, if the floor is not flat, the result will not last.

Self-levelling screeds bring a modern and practical solution to this problem. They are applied in a short time and retain their smoothness for many years.

For this reason, quality materials should always be preferred in professional applications. High-performance products such as KraftBau Self-Levelling Screed provide not only a smooth surface but a durable and long-lasting structure.