EÜK screed-covered duct system

The EÜK system from OBO is one of the most popular underfloor systems. Planners around the world rely on its variety, reliability and flexibility. Thus, in cooperation with OBO, numerous challenging construction projects have been completed. The EÜK system can stand up to all the requirements on the building site and during later use.

Experts in the underfloor sector

The screed-covered duct system from OBO is the first underfloor system as we know it today in Europe. The system was presented for the first time in 1965 and, since then, has been continually adapted to installation practices. For five decades now, planners, architects and customers have relied on the tried-and-trusted technology. This is particularly important for creating a high level of flexibility in underfloor electrical installations.

Robust and versatile

Whether cement screeds, poured asphalt, floating screeds or heated screeds – the EÜK system is suitable for all screed types. Changes to the floor covering do not represent a problem. Here, the system can be used for a wide range of floor coverings (stone, marble, wood, textiles, plastic coatings, etc.). At the same time, this system can be combined with dry, moist or wet-care floor coverings.

Expansion a heavy-duty system

Depending on the construction project, the system offers solutions for floor structures with increased load requirements. The EÜK system can be expanded into a heavy-duty system. The load capacity of the EÜK system has been tested to DIN 50085-2-2. The completely closed duct system protects the routed cables and repels footfall, dust and dirt during everyday construction site work.

Easy mounting

The underfloor ducts and underfloor boxes of the EÜK system from OBO are mounted directly on the raw concrete. To protect against heat losses and ensure the reduction of footfall sound, insulation layers are inserted. These insulation layers surround the duct system completely. A combination with underfloor heating in the screed is also possible. Here, the duct system is below the underfloor heating and is thus completely separate in the insulation layer.

The solid system shows its strengths during the construction phase. It is completely closed during the entire mounting operation. The underfloor sockets are protected by the mounting protection lid. As such, no foreign bodies can ingress into the system and the interior remains clean. The underfloor sockets in the three basic heights cover a large height adjustment range of between 70 and 220 mm screed height. In addition, the underfloor sockets of the duct system are decouplable, so that they float in the screed. This decoupling avoids cracks in the neighbouring floor covering and screed.

The sockets, data and multimedia connections can be installed flexibly using the OBO Modul 45 series. These modules can be installed using universal supports in all device installation units. These device installation units are available in the form of modular cassettes and service outlets.

Installation principle


Underfloor installation duct


Duct connection bracket


Connection shackle


Vertical bend


Underfloor device socket with mounting lid and lid blanking plate (UGD)


Underfloor junction and branch box (UZD)


Duct end closure piece

Noise and fire protection-tested

The duct system fulfils the noise protection requirements for civil engineering. For this, after screed laying, the cover frame of the underfloor socket can be decoupled from the socket base. The frame now floats, without any direct connection to the raw concrete, on the screed plate. This separation means that no noise can be transmitted via the duct system and the underfloor socket. The EÜK screed-covered duct system can also be installed in escape and rescue routes and through fire walls. For this, special OBO cable insulation is necessary. The closed design means that the duct system is suiable for excellent cable protection, tidiness in the cable system and electromagnetic shielding. This shielding is also guaranteed during the construction phase.

Sloping duct entries

The prepared duct openings of the underfloor boxes of the EÜK system also allow a change of direction or sloping duct insertion (up to 7°) without an adjustment cut. Sloping duct insertions with an angle of greater than 7° can be created with an appropriate adjustment cut. This adjustment cut must be performed according to the socket size and the insertion opening.

Duct directional corrections

Sloping duct entries

Selection aids

Installation of OBO's screed covered underfloor system EÜK with underfloor box UZD

Additional information