Schlüter-BEKOTEC-EN-FK  Lightweight studded screed panel

The reliable Schlüter-BEKOTEC-EN 12 FK covering assembly technology is a system for crack-free and functionally safe screeds and heated screeds, with coverings made of ceramics, natural stone and other covering materials.

The bonded assembly is installed directly on load-bearing, weight-distributing substrates, such as concrete, existing screeds or wooden ceiling structures. The thin-set mortar must be suitable for the corresponding substrate according to manufacturer specifications. The suitability of the substrate for heating purposes has to verified (movement joints, edging strips, etc.).

This system is based on the BEKOTEC-EN 12 FK studded screed panel with anchoring fleece on the underside. The studded screed panel as a bonded assembly is installed directly on suitable weight-distributing substrates using the thin-bed method. The geometry of the BEKOTEC-EN 12 FK studded panel dictates a minimum screed layer thickness of 20 mm between and 8 mm above the studs. The stud spacing allows for clamping the heating pipes of the system, which have a 10 mm diameter, in a 50 mm grid to produce a heated screed.

Since only a relatively small amount of screed has to be heated or cooled (with a coverage of 8 mm, approx. 40 kg/m² ≙ 20 l/m²), the floor heating system is easily adjustable and ideally suited for operation at low supply temperatures.

The curing stresses that occur in the screed due to shrinkage are absorbed by the studded pattern. Tensions resulting from deformations can therefore not affect the entire area, and it is not necessary to install movement joints in the screed. Once the cement screed is ready to support weight, the Schlüter-DITRA uncoupling mat (alternatively, Schlüter-DITRA-DRAIN 4 or Schlüter-DITRA-HEAT) can be installed (gypsum-based screed ≤ 2 CM %). Ceramic tiles or natural stone can then be installed directly over this layer, using the thin-bed method. Movement joints in the covering layer have to be created with Schlüter-DILEX according to industry standards.

Cover materials that are not susceptible to cracking, such as parquet or carpeting, are installed directly over the screed as soon as it reaches the corresponding residual moisture level.

Further information can be found in our Technical Manual.

Technical data

1. Stud diameter: approx. 44 mm
   Installation spacing: 50, 100, 150 mm, etc.
   Diameter of system heating pipes: 10 mm
   The studs have a cutback design to securely keep heating pipes in place without the need for clamps.
2. Connections:
   The studded panels are connected by overlapping a row of studs and clicking the panels together.
3. Working area: 1.1 x 0.7 m = 0.77 m²
   Panel height: 12 mm
4. Packaging: 10 units/box = 7.7 m²
   Box dimensions are approx. 1160 x 800 x 80 cm.

• Warranty:
  Schlüter-Systems offers a five year warranty for the life of the covering assembly, provided all installation instructions were observed and the covering is used as intended.
• Crack-free covering:
  The BEKOTEC system is designed to reduce shearing tensions of the screed within the grid of the studded panel. No construction reinforcement is required.
• Non-buckling construction:
  The covering assembly of the BEKOTEC system is free of inherent stresses. Consequently, no buckling can occur in the area. This applies in particular to stresses resulting from temperature fluctuations, e.g. in heated screeds.
• Joint free screed:
  No expansion joints are needed in the screed since the BEKOTEC system evenly distributes any shearing tension in the screed across the entire area.
• Movement joints in the joint pattern of the tile or stone covering:
  The BEKOTEC system allows for aligning the design of movement joints to the selected joint pattern of the covering for tile or paver coverings since expansion joints from the screed do not have to be continued into the top covering. The applicable regulations for the placement and construction of movement joints in and around the tile field must be observed.
• Short construction time:
  As soon as the screed produced with the Schlüter®-BEKOTEC system is able to support weight, coverings of ceramic tile, natural stone or artificial stone can be directly installed on top of the Schlüter®-DITRA membrane. Ceramic thermal comfort floors are ready for heating only seven days after the completion of the cover assembly.
• Material savings:
  With a screed coverage of 8 mm, only approx. 40 kg/m² ≙ 20 l/m² screed volume is needed.
• Fast-responding floor heating system:
  Compared to conventional heated screeds, cover assemblies installed with a Schlüter®-BEKOTEC-THERM ceramic thermal comfort floor react much faster to temperature changes, since the volume to be heated or cooled is much lower. This allows for operating the floor heating system in the low temperature range to save energy.

1. Install Schlüter-BEKOTEC-EN 12 FK as a bonded assembly by adhering the anchoring fleece on the underside to a load-bearing and level substrate. The substrate must be free of components that may inhibit bonding, load bearing and level. Any necessary levelling work must be completed before installing BEKOTEC-EN 12 FK.

   The selection of the adhesive for installing BEKOTEC-EN 12 FK depends on the substrate. The adhesive must bond with the substrate and mechanically attach to the BEKOTEC-EN 12 FK anchoring fleece. A dry-setting thin-bed tile adhesive can be used for most substrates. Review any potential material incompatibilities beforehand. Apply thin-set mortar on the substrate with a notched trowel (recommended size: 6 x 6 mm).

2. Adhere the 8 mm edge strip Schlüter®-BEKOTEC-BRS 808 KSF in places where the covering adjoins walls and other construction elements.

   The adhesive leg integrated into the edging strip features a self-adhesive strip on the underside for attachment. The adhesion on the substrate and the pre-tensioning of the integrated foil leg push the edge strip toward the wall. When the Schlüter-BEKOTEC studded panel is adhered to the top of the adhesive leg, the panel bonds with the substrate and flowing screed can no longer flow underneath the panel.

3. Fully embed the BEKOTEC-EN 12 FK studded panels in the adhesive, creating a bond with the anchoring fleece. The curing time of the adhesive must be observed. The BEKOTEC-EN 12 FK studded panels must be precisely cut to size in the edge areas. Connect the BEKOTEC panels by overlapping a row of studs (see picture).

   In threshold areas and near distributor boxes, the Schlüter-BEKOTEC-ENFGK smooth levelling panel may be used to simplify the pipe installation. It is adhered by bonding the anchoring fleece on its underside to the load-bearing and level substrate. If necessary, use the supplied double-sided adhesive strip to attach the studded panels to the levelling panel. The Schlüter-BEKOTEC-ZRKL 10/12 self-adhesive pipe clamping strip enables precise pipe layout in these areas.

4. Once the thin-bed mortar has fully cured, clamp the system pipes with a diameter of 10 mm between the cutback studs to create a Schlüter-BEKOTEC-THERM floor heating system. The spacing of the pipes must be determined based on the required heating output, as shown in the BEKOTEC heating diagrams.
5. As part of the screed installation, fresh cement screed of screed quality CT-C25-F4, max. F5 or gypsum-based screed CA-C25-F4, max. F5 is installed with a minimum screed cover of 8 mm over the studded panels. The layer thickness can be partially increased to max. 15 mm for levelling. Suitable flowing screeds CAF/CTF with the corresponding specifications may be used as well. Observe the system approval for this application.

   Note: Please contact our Technical Department in advance to discuss different screed properties for specific projects.

   To prevent impact sound transmission between two rooms, separate the screed in the relevant places with the Schlüter-DILEX-DFP expansion joint profile.

6. The Schlüter-DITRA uncoupling mat (alternatively, Schlüter-DITRA-DRAIN 4 or Schlüter-DITRA-HEAT) can be installed in accordance with the installation instructions of product data sheets 6.1 (alternatively, 6.2 or 6.4) as soon as the screed is ready to bear weight. The uncoupling mat can be installed over gypsum-based screeds as soon as they have reached a residual moisture level of 2 CM % or less.
7. Ceramic tile or natural stone coverings can then be installed directly on top of the uncoupling mat, using the thin-bed method. Divide the covering above the uncoupling mat into fields, using movement joints in accordance with the applicable regulations. We recommend the Schlüter-DILEX-BWB, Schlüter-DILEX-BWS, Schlüter-DILEX-KS or Schlüter-DILEX-AKWS profiles for creating movement joints (see product data sheets 4.6 - 4.8 and 4.18).
8. Install the Schlüter-DILEX-EK or Schlüter-DILEX-RF corner movement profile as a flexible perimeter movement joint in the area of the floor-wall transition (see product data sheet 4.14). Cut off the protruding part of the BEKOTEC-BRS 808 KSF edging strip in advance.
9. If the BEKOTEC-THERM ceramic thermal comfort floor is to function as a floor heating system, the full covering assembly is ready for heating only seven days after completion. Start from a water temperature of 25 degrees C and increase the supply temperature by no more than 5 degrees C a day until the desired usage temperature has been reached.
10. Covering materials that are not susceptible to cracking (e.g. parquet, carpet or vinyl coverings) can be installed without the uncoupling mat, directly on top of the BEKOTEC screed. The screed thickness must be adjusted to the relevant material thicknesses. In addition to the applicable installation guidelines, note the permissible residual moisture level of the screed for the selected covering material.

Schlüter-BEKOTEC-EN 12 FK is made of high-impact structured polystyrene with an anchoring fleece and is suited for use with conventionally applied cement or gypsum screeds as well as flowing screed.