Excellent design solution especially there where is a need for large-span roofs and flat and smooth bottom surface of the ceiling structure.


If we remove an unnecessary weight from the construction while maintaining two-way operation, as a consequence, we will obtain a durable structure with interpenetrating quasi-beams, between which there is emptiness, created by plastic inserts. Empty plastic inserts protected with steel rods are placed between the bottom and top steel reinforced concrete slab.

They are placed in areas where there is no structural benefit from the use of concrete (as in profiles of rolled steel I-beam type). Thanks to this simple treatment the weight of the floor can be reduced up to 35% compared with conventional (massive) ceiling structure with the same parameters. This gives a possibility of achievement the span lenghts up to 18m-20 m while maintaining economical solutions (required slab thickness approx. 60cm) - multi-span systems. Particularly preferably a ceiling structure is being shaped with a span of approx. 10-12m and thicknes of approx. 40cm.

The dimensioning of the COBIAX ceiling structure as a two-way flat ceiling structure can be executed by conventional methods dimensioning of massive slabs in accordance with current standards for the construction of reinforced concrete. It should only be taken into account the reduced self- weight and zone where lateral force is greater than the border force (essential massive areas - without inserts).


  • Light and working bidirectionally - up to 35% lighter ceiling structure relative to the concrete ceiling structures (reduce the self-weight of 1.3 to 4,8kN / m2),
  • Large-span ceiling structures - up to 20m (multi-span systems),
  • Lack of support beams - flat surfaces,
  • Any shape of the floor slab,,
  • Easy to change the function of use, not limited by linear supports, allowing architects to not limited creativity,,
  • Reduction poles, foundations, earthworks,
  • Resistance to earthquake (weight reduction of horizontal elements),
  • In comparison to traditional unidirectional hollow-core particle boards, the Cobiax ceilings do not bend under pressure.
  • Easy to "connect" with other technologies of ceiling structures.


The Cobiax ceiling structures can be used wherever we design traditional monolithic or composite celings structures which due to technological and economic advises the cross-reinforced ceiling structures are recomended based on pillars, so that we give up beams and substrings which has an impact not only on reducing the consumption of concrete but also to reduce the capacity and it is already a fixed operating cost of savings facility.