BWC 55 light with balcony box 55-4

The system consists of several components:

Block-out box in the floor slab:
If used, the block-out box is cast into the floor slab and anchored using the specified anchorage reinforcement.

Outer tube:
The outer tube can either be cast directly into the floor slab or inserted into a previously installed block-out box. It is important that the outer tube extends sufficiently beyond the slab edge so that it projects beyond the external sheathing/wind barrier. This provides easy access for sealing around the outer tube against the sheathing/wind barrier using sealant, membrane, tape or similar products.

Inner tube:
The inner tube is the component that connects the floor slab to the balcony or access balcony element. It is available in several versions. The most common version is used in combination with a cast-in BWC 55-4 balcony box or supplied with a welded angle bracket. Where the balcony or access balcony is cast in situ, the inner tube is extended into the balcony structure and the reinforcement is connected directly to the inner tube.

BWC 55-4 Balcony Box:
The BWC 55-4 is the component cast into the precast concrete element by the precast concrete manufacturer. It provides generous installation tolerances in both the vertical and horizontal directions.

The box is equipped with an adjustment bolt for vertical adjustment and horizontal locking of the element. It also incorporates a grouting tube, allowing the connection to be grouted after installation has been completed.

Function and Construction

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

Impact Sound Reduction and Thermal Break

Two integrated elastomeric elements 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 a part of the building envelope through which heat is transferred more readily than through the surrounding construction. Minimising thermal bridges is therefore important in energy-efficient buildings.

The integrated elastomeric elements provide a thermal break between the inner and outer tubes, reducing heat transfer through the connection.

Applications

The system can be adapted to a wide range of construction methods, including cast-in-situ concrete slabs, filigree slabs, hollow-core slabs and cross-laminated timber (CLT) floors.

In combination with our stair connection system, the solution can also be used where balconies are recessed into the building.

The system can also be adapted for refurbishment and conversion projects, for example where existing office buildings are converted into residential buildings and new balconies are required.

Fire Resistance

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

The solution can be designed for fire resistance classes R30, R60, R90 and R120, depending on the specified concrete cover.

Documentation and Design

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

The EPD provides third-party verified documentation of the product's environmental impact throughout its life cycle and can be used as supporting documentation for the project's sustainability and environmental objectives.

The European Technical Assessment (ETA) documents the product's performance and fitness for its intended use in precast concrete structures. CE-marked production in accordance with EN 1090 ensures traceability, factory production control and documented quality in accordance with applicable European requirements.