Bonded screed | Price, DIY, Advice and Information
Screed floor build-up 11 - Choose a different floor structure
1 cm to 5 cm - with concrete slab as substrate - non-moisture-sensitive floor covering such as tiles
Information
A bonded screed is applied to a concrete slab when you want to level your floor between 1 cm and 5 cm.
A bonded screed is bonded to the underlying floor slab and is always prepared with a bonding slurry or primer layer.
Before starting, the floor slab must be solid and free of cracks, and the surface must be dry, free of grease and dust.
Advantages
- Achieve a perfect end result without experience
- Compartmentalization of the screed = crack-free screed
- Screed is much cheaper than self-levelling compound.
- Spreading screed work over several days (no stress during placement)
- Replaces the steel reinforcement mesh = saving an average of 3 euros/m²
- Due to the low thicknesses, there is less weight on the supporting floor.
Side view of floor structure
Legend
- Concrete
- Bonding layer + optional epoxy primer against moisture
- Staenis bonded screed grid (thickness from 1 cm to 5 cm)
- Apply edge insulation if necessary
- Screed with 250 kg/m³ cement
- Double bonding with S1 Flex Tile Adhesive
- Non-moisture-sensitive floor coverings such as tiles
- Water-repellent, colored joint mortar
- Skirting board
- Flexible silicone
Introduction to Bonded Screed
Bonded screed is a popular flooring solution, used for levelling and stabilizing floors with a thickness between 1 cm and 5 cm. This article provides you with comprehensive information about bonded screed, including the price, DIY tips, advice, and other important information to help you make an informed decision.
What is Bonded Screed?
Bonded screed is a type of floor screed that adheres directly to the concrete substrate, creating a strong bond between the two surfaces. It is often prepared with a bonding layer or primer to ensure good adhesion. This type of floor is suitable for various applications and is an excellent choice for levelling and stabilizing uneven floors.
Why choose Bonded Screed?
There are several advantages associated with the use of bonded screed, such as:
- Achieving a perfect finish without prior experience
- Compartmentalization of the screed for crack-free results
- Lower costs compared to other levelling solutions
- The possibility to spread the work over several days
- Replacement of traditional iron reinforcement mesh, with an average saving of €3/m²
- Reduced weight on the load-bearing floor due to reduced thickness
Preparation of the substrate for Bonded Screed
To ensure a successful installation of bonded screed, it is crucial to properly prepare the concrete substrate. This includes:
- Ensure that the concrete is strong, stable, dry, clean, and free of dust and contaminants
- Removal of loose or damaged parts that may interfere with adhesion
- Temporarily disable any underfloor heating
Applying a primer to the substrate
Applying a primer to the substrate is essential for a strong bond between the bonding screed and the concrete. There are various primers available, depending on the specific needs of your substrate. For example, use a primer for absorbent surfaces, such as Primer CodeX FG 300, on dry concrete and a bonding primer for non-absorbent surfaces. In case of slight moisture problems, use an epoxy primer such as UZIN PE 460 A/B. Always consult technical datasheets for guidance when dealing with damp or contaminated substrates.
Installing the Staenis compound levelling grid
The Staenis grid levelling grid is a unique levelling grid that helps create a perfectly flat surface for the bonding screed. This innovative system allows you to start with a thickness of just 1 cm, ensuring a precise and efficient installation. Follow the guidelines for setting up the grid and adjusting it to the correct height.
The preparation and application of the Barbotine (Cement slurry)
The barbotine, also known as cement slurry or cement paste, is a crucial component for achieving a strong bond between the bonding screed and the concrete substrate. Mix the barbotine according to the recommended ratios and apply it to the prepared substrate with a brush. Apply the screed mixture while the barbotine is still wet for optimal adhesion.
Laying the Bonded Screed
Once the slurry has been applied, you can start laying the bonding screed. Spread the screed mixture evenly over the surface, using the Staenis grid levelling grid as a guide to achieve the desired thickness. Make sure to apply the screed mixture while the slurry is still wet to prevent detachment and hollow sounds.
The curing and drying of the Bonded Screed
After applying the bonding screed, it is important to allow it to cure and dry properly. This ensures a stronger and more stable floor. Cover the freshly applied screed with a foil to prevent it from drying out and hardening too quickly. Take the recommended drying time into account before proceeding with the next steps.
Finishing of the Bonded Screed
When the screed is fully cured and dried, you can finish the floor with tiles or other floating floor coverings. Use double bonding with S1 Flex Tile Adhesive for optimal adhesion. Also make sure to use a water-repellent, colored grout to protect the tile joints.
If there is a risk of rising damp from the subfloor, it is important to take precautions when installing floor coverings. You can use tiles or vapor-permeable floor coverings to minimize moisture problems. If necessary, you can also seal the subfloor to prevent moisture from penetrating.
When installing laminate, it is a good idea to first apply a foil to serve as a moisture barrier. After that, you can install the underlay and then the laminate.
Skirting boards and joint finishing
Don't forget to install skirting boards to neatly finish the edges of the floor and to apply a smooth silicone joint where the floor meets the wall. This helps to keep moisture out and ensures a professional finish.
Conclusion
Bonded screed is an excellent choice for levelling and stabilizing floors between 1 cm and 5 cm thick. With proper preparation, the use of a Staenis grid levelling grid, and by following the recommended installation and finishing methods, you can create a durable and attractive floor. With the tips, advice, and information on this website page, you are well on your way to achieving a successful bonded screed installation.
Installation video
We deliver screed in a silo to your home (only in Belgium)
With a simple press of the button on the silo, you can produce fresh sand-cement screed at a rate of 3 m³/h, and this without time pressure to process the large quantity of sand-cement screed.
There are actually 2 separate compartments in the silo. One part is filled with sand (0/4-0/7mm) and the other part is filled with dry cement (250kg/m³). These are only mixed with water at the moment you wish.
The big advantage of this is that you can make fresh sand-cement screed at your own pace and for several weeks.
We deliver screed in bags to your home
Fast: Fast-drying, fibre-reinforced screed with only 2/3 of the weight compared to traditional screed. This makes the work significantly less heavy when working with bagged material instead of traditional screed. Ideal for applying a bonded screed floor or for small spaces, both indoors and outdoors. This Fast screed is easy to spread, allowing you to achieve a flat finish more quickly. When bonded to concrete, Latermix Fast requires a minimum thickness of 2.5 cm, which may be reduced locally to 1 cm. Apply the screed wet-on-wet onto a fresh bonding slurry of cement, latex and water, following the technical data sheet (Latex CS). The 1 cm exception applies only to local areas, not to the entire floor. Tip for thin areas: mix with approximately 2 litres of water per bag to achieve an earth-moist consistency. If site conditions require it, the water quantity may be increased slightly to improve workability, as stated in the technical data sheet. Additional water may extend the drying time. Apply the screed onto the still-fresh bonding slurry and compact thoroughly.
Enter the screed thickness. Measure from the base on which the screed starts to the top of the screed.
Do not include flooring, adhesive or other layers above.
Enter the combined thickness of the insulating screed and screed. Measure from the base beneath the insulating screed to the top of the screed.
Do not include flooring, adhesive or other layers above.
Enter the thickness of the stabilised sand bed. Measure from the base beneath the sand bed to the top of the sand bed.
Do not include flooring, adhesive or other layers above.
Enter the drainage mortar thickness. Measure from the base beneath the drainage mortar to the top of the drainage mortar.
The screed used to smooth the surface is calculated separately. Do not add extra thickness for it; also exclude adhesive and tiles.
Do not include OSB in this thickness.
Enter the insulating screed thickness. Measure from the base on which the insulating screed starts to the top of the insulating screed.
Do not include OSB or other floor boards on top of the insulating screed. Any screed, adhesive and flooring above are also excluded from this measurement.
Enter the insulating screed thickness. Measure from the base on which the insulating screed starts to the top of the insulating screed.
Do not include the separately calculated levelling compound, adhesive or flooring above.
Do not include OSB in this thickness.
Enter the height of the dry fill in the grid. Measure from the base beneath the grid to the top of the filled grid.
Do not include OSB or other floor boards on top of the system. Underfloor heating, adhesive and flooring above are also excluded from this measurement.
Enter the thickness of the levelling compound layer. Measure from the surface to be levelled to the top of the levelling compound.
Do not include flooring, adhesive or other layers above.
Do not include OSB in this thickness.
Enter the adjusted system height. Measure from the surface supporting the feet or adjustment screws to the top of the supporting structure.
Do not include OSB or other floor boards on top of the system. Underfloor heating, adhesive and flooring above are also excluded from this measurement.
Do not include OSB in this thickness.
Enter the height of the CircoFloor system with fill. Measure from the base on which the adjusting screws stand to the top of the CircoFloor structure.
Do not include OSB or other floor boards on top of the system. Underfloor heating, adhesive and flooring above are also excluded from this measurement.
First select a filling material in the calculator to see its thickness explanation.
