Schlüter-BEKOTEC is an underlayment which allows for easier installation, and is far less labour-intensive than traditional floor construction. It assures a crack-free ceramic tile and natural stone covering above a screed and insulating layer. The screed can be installed with or without underfloor heating pipes. Surface movement joints are only required in line with industry recommendations, and can therefore be incorporated to suit any aesthetic design of the tiled floor.
A studded polystyrene panel is placed either directly over a load-bearing substrate, or over traditional acoustic/heat insulation. Stress build-up due to shrinkage, which occurs during the curing of the screed, is successfully eliminated by the formation of micro-fine cracks, doing away with the need for movement joints in the screed.
Basically, the studs on the panel result in an intentional weakening of the underside of the screed layer through their even spacing. When the screed shrinks, the network of micro-fine cracks forms between the studs. Consequently, the screed slab loses its compressive stresses, so the forces causing curling and cracks simply cannot accumulate.
As soon as the screed can be walked on, the Schlüter-DITRA uncoupling membrane is bonded to it, and ceramic tile or stone coverings are then installed on top, incorporating surface movement joints in line with industry recommendations. Coverings which don't crack -- such as carpet and vinyl -- can be fitted as soon as the screed has dried sufficiently.
Because of its lighter weight and lower assembly height, it is installed faster than traditional underlays, the screed does not curl, and, most importantly, the surface coverings are guaranteed crack-free.
Heat or sound insulation can be placed below the system to comply with building regulations - something which, with traditional methods, can be a major problem when applying rigid surface coverings such as ceramic tile and stone.
However, if heat or sound insulation is required below the screed, it should be selected to conform to the applicable standards, and must be rated for the particular live and dead load exposure. Obviously problems may arise if unsuitable materials have been used in the flooring assembly. But problems which do occur can be repaired by cutting out the damaged areas, and repairing from the underlayment system through to the surface covering.
The suitability of the system to withstand high loads in individual applications should be verified. However, the breaking tests performed on the modular system exceeded the 2 KN/M2 required by DIN 1055 for residential and commercial applications such as offices, public buildings and car showrooms.
An "Expert Report" prepared independently by IFF Koblenz, a well-established name in the German flooring industry, concluded that Schlüter-BEKOTEC's modular technology can "rightly be considered a new and innovative solution for common problems on today's construction sites."
The report states that the system gives:
- No warping or curling of the screed slab
- No cracks in covering materials made of ceramic or stone tiles
- Sufficient live loads for the application areas up to 5 kN/m2, depending on insulation materials
- Low construction height
- Fast installation times
- Time-saving and cost-efficient construction processes
- Economical energy utilisation in floor heating systems.