BWC 55-740 with balcony box 55-4

The system consists of several components:

Recess Box in the Slab:
Where this option is used, the recess box is cast into the slab and anchored using the specified anchorage reinforcement.

Outer Tube:
The outer tube can either be cast directly into the slab or inserted into a previously installed recess box. This model incorporates a clamping flange system against the external sheathing board, providing an effective weather-tight seal and preventing water ingress.

Where the outer tube is cast directly into the slab, we recommend using our 700 × 700 mm rubber membrane. The membrane accommodates any construction tolerances arising during casting and is bonded to the external sheathing board to provide a weather-tight connection.

Inner Tube:
The inner tube connects the floor slab to the balcony or access balcony element and is available in several configurations. The most common configuration is used in combination with the cast-in BWC 55-4 Balcony Box. Alternatively, the inner tube can be supplied with a welded steel angle.

For in-situ cast balconies or access balconies, the inner tube is extended and the reinforcement is connected directly to the inner tube.

BWC 55-4 Balcony Box:
The BWC 55-4 is cast into the precast balcony element by the precast concrete manufacturer. The unit provides generous vertical and horizontal installation tolerances.

It is equipped with an adjustment screw for vertical levelling, which also locks the element horizontally. An integrated grouting tube allows the connection to be fully grouted after installation.

Function and Construction

All components are manufactured from S355 structural steel and are hot-dip galvanised for corrosion protection.

Impact Sound Reduction and Thermal Bridge Reduction

Two integrated elastomeric units between the inner and outer tubes reduce the transmission of impact and structure-borne sound through the balcony support connection. This contributes to good acoustic performance in the completed structure.

A thermal bridge is an area of the building envelope where heat is conducted more readily through the construction than through the surrounding materials. Minimising thermal bridges is therefore important for reducing heat loss and achieving an energy-efficient building envelope.

The integrated elastomeric units provide an effective thermal break, reducing heat transfer through the balcony connection.

Applications

The system can be adapted to a wide range of construction methods, including:

• In-situ cast concrete slabs
• Filigree/semi-precast slabs
• Hollow-core slabs
• Cross-laminated timber (CLT) slabs

In combination with our stair connection system, the BWC system can also be used for recessed or inset balconies within the building.

Fire Resistance

When cast into concrete, the load-bearing steel components are protected against elevated temperatures by the concrete cover.

Depending on the specified concrete cover, the connection can be designed to achieve fire resistance classes R30, R60, R90 and R120.

Documentation and Structural Design

Technical documentation, EPD and BIM objects support efficient structural design, documentation and digital collaboration throughout the construction project.

The EPD (Environmental Product Declaration) provides third-party-verified information on the product's environmental impacts throughout its life cycle and can be used as supporting documentation for the project's sustainability and environmental objectives.

The ETA (European Technical Assessment) documents the product's performance and suitability for its intended use in precast concrete construction.

CE-marked production in accordance with EN 1090 ensures traceability, factory production control and documented quality in accordance with applicable European requirements.