Screeding a floor is important in preparing a surface for final finishes such as carpet, tiles, or wood. This act involves laying a leveling layer of material over a subfloor to ensure a smooth, even base that enhances both aesthetics and functionality. If you are a professional tradesperson or a DIY enthusiast, understanding how to screed a floor is important in achieving a great result.

Below is a guided process on how to screed a floor.

What Is Screeding?

Screeding is the application of a thin layer of leveling material over a subfloor, the layer which is known as screed, is designed to give a level and flat surface for subsequent flooring treatments.

Choosing the Correct Screed

Before screeding a floor, it is important to know the appropriate screed type for the project. All screed types vary, and elements of the screeding process, such as preparation, drying time, and thickness depend on which variety of screed you applied.

The commonly used types of screeds used across different projects are:

1. Bonded Screed: A bonded screed that is bonded to a concrete subfloor with the use of a primer. For thinner screed applications, bonded screed is often advised to be used.
2. Unbonded Screed: Just as the name, unboned screed is not bonded directly to the concrete subfloor, but rather on a damp-proof membrane. This protects your floor from moisture in the subfloor.
3. Floating Screed: This is a type of unbonded screed that is mostly applied on a layer of insulation, such as underfloor heating.

Another type of screed such as self-leveling liquid screed, has been made popular over the years, but due to the industrial machinery needed to mix and apply this form of screed, it is recommended to hire an experienced and certified expert to do this.

Tools and Materials Needed to Screed

Before starting to screed, you have to have the following tools;

1. Screed Mix: This could be an already mixed screeding compound, it all depends on the projects.

2. Mixing Tools: This could be a mixing bucket or a portable mixer, the work of these is to prepare the screed mixture.

3. Trowel or Spreader: This work of this is to apply and spread the screed.

4. Screed Leveling Bar: The level bar is to ensure the screed is applied evenly.

5. Spirit Level: This is an important tool, as it is needed to check the level of the screed.

6. Protective Gear: Protective gear like gloves, safety glasses, and appropriate footwear are needed. 

Preparing the Subfloor

Clean the Concrete floor: The first step to preparing a subfloor for screeding is to clean the floor, this can be done by removing the debris, dust, or loose materials from the subfloor. A clean subfloor ensures better adhesion of the screed.

Check for moisture: Excess moisture can affect the screed’s bonding and curing, so one must ensure the subfloor is dry.

Apply a Primer: First, you must consider the type of screed and subfloor, applying a primer can enhance adhesion. Make sure to follow the manufacturer’s instructions before applying the primer.

Mixing the Screed

1. Follow the ratio: Make sure to follow the manufacturer’s recommended ratio. Ideally, a ratio of 3 parts sand to 1 part cement is used, but also bear in mind that this can vary based on the type of screed.

2. Mix Thoroughly: The next step to mixing the screed is to combine the dry materials first, then add water gradually while mixing. Over-watering can weaken the screed, so make sure that the paste is as thick as that of a pancake batter.

3. Let the Mix rest: Let the mixture rest for some minutes to let the materials fully absorb the water. Then, give it a final mix before application.

Applying the Screed

1. Pour the Screed: Pour the screed mix onto the prepared subfloor. Work in small sections to prevent the screed from drying out before you finish.

2. Spread Evenly: The next step is to use a spreader or towel to spread the screed over the surface. Work the screed into place, ensuring it fills any gaps and covers the subfloor uniformly.

3. Level the Screed: Here you have to use a screed leveling bar or a straightedge to level the surface. Drag the bar across the surface to remove excess screed and fill in low spots. Maintain a consistent level by checking on a spiritual level.

4. Smooth the Surface: Immediately after leveling, you have to use a trowel to smooth the surface of the screed. This has to be done to achieve a professional finish.

Curing and Drying

After the application of the screed, the next step is the curing and drying.

1. Allow to cure: It’s advisable to follow the manufacturer’s instructions to let the screed cure. It takes about 24 to 48 hours for the initial setting, while full curing takes weeks.

2. Protect the Screed: The screed should be protected from extreme temperatures, direct sunlight, or heavy traffic during the curing period. The screed could be covered with plastic sheeting or damp cloths to prevent rapid drying.

3. Check for dryness: Ensure the screed is completely dried and has reached the required strength before proceeding with the final flooring.  

Final Tips

1. Work Quickly: Work efficiently and avoid delays as possible, because screed can set quickly.
2. Regular Checks: Always check for smoothness and levelness throughout the process.
3. Follow Guidelines: Always follow the specific guidelines provided by the manufacturer for optimal results.

Conclusion

Screeding a floor is a precise and essential task in ensuring a level and smooth surface for your floor finish. By carefully preparing the subfloor, selecting the right screed mix, and applying the screed correctly, you can achieve a pro-quality result. If you are working with a contractor, or it is just a DIY project, it’s important to follow the process, follow the listed steps to achieve the best outcome for your flooring needs.

Frequently asked questions

At Concrete King our team of experienced, highly trained, and fully certified experts have got you covered in all types of screedings.

Clients across London, Kent, Essex, and beyond, have trusted us with their screedings and were glad they did, as we are known for delivering excellent floor screedings to our clients. We don’t just deliver to our clients, we deliver with our state-of-the-art Vehicles, and our deliveries are swift and jobs come out with optimal results.

Have any questions about screeding? Worry no more we have you covered. Speak to us today, as our experienced team is ready to help out!