FACADE SUBSTRUCTURES

FACADE SUBSTRUCTURES

>> Structural components of the VCW facade system 07 >> Products and Fastening solutions for the VCW 18

Ventilated curtain walls (VCWs) have been established in the construction industry in Germany and Europe for decades. Over this time they have proven their worth as rugged construction systems requiring very little maintenance. Moreover, ventilated curtain walls enable architects to create a wide range of fascinating designs. GIP GmbH is a manufacturer of metal substructure systems for VCWs and an experienced consulting partner in all technical matters relating to the design, planning and realisation of ventilated curtain walls. This document provides a brief description of the basic planning...

General A ventilated curtain wall (VCW) is a facade system composed of multiple layers, in which the supporting external wall is provided with a facing that offers protection against the weather. The facing can be made from a wide variety of materials: ceramic, metal, fibre cement, composite panels, natural stone etc. The substructure attaches this facing to the solid outer wall while leaving a gap between the two. Mechanism Wind and thermal effects due to warming create a circulation of air in the ventilation space. This circulation transports away the moisture in the ventilation space caused...

STRUCTURAL COMPONENTS OF THE VCW FACADE SYSTEM The typical structure of the facade system is shown below. 1_ Wall brackets 2_ Facade anchors 3_ Facade fastener anchors 4_ Vertical profiles 5_ Thermal insulation 6_ Ventilated substructures 7_ Fastening elements for the cladding (rivets, ceramic clips, polymer adhesives etc.) 8_ Cladding panels (ceramic, metal, fibre cement, composite)

Facade anchors approved by the building authorities must be used to anchor the VCW to the supporting external wall. The optimum anchors are selected for use in each project based on considerations such as the materials used in the construction of the supporting external wall and the prevailing loads. For VCWs, the most commonly used anchors are plastic anchors with galvanised screws. Suitable insulation materials: Only mineral wool materials may be used for the insulation of VCW. These must comply with DIN 18516 and hence be non-flammable and absorb very little moisture. Standard insulation thicknesses...

Substructure The substructure transmits the load of the cladding itself and the wind load to the enclosing external wall. Metal substructures are generally used as these can compensate for tolerances in the shell construction. Most systems consist of a two-part construction, which is fastened to the supporting external wall using a ­ nchors. This base construction is aligned plumb and flush and acts as a support for installing a variety of facade cladding materials. The substructure system must be designed in such a way that materials used can expand due to temperature changes without creating...

PLANNING A VCW When designing a VCW, as in all construction projects, proper planning and execution determine the quality of the finished facade. Although damage to ventilated curtain walls is extremely rare compared with other systems, and is usually due to incorrect execution, careful planning that considers all the basic conditions applicable to the specific object is required. In Germany, a range of regulations, which are continuously updated give planners and installation companies the necessary security in the areas of invitations to tender, execution and billing. Technical regulations...

Calculation of the thermal transmission rating /  Consideration of thermal transmission German Energy Saving Regulation (EnEV) A building’s thermal insulation certificate is based both on its primary energy consumption and the calculated heat loss through the external wall. In the case of VCWs, there has been growing interest in the thermal bridge effect of the bracket design over recent years. This energy loss is classified for each bracket using the thermal bridge point loss coefficient. It is possible to reduce the energy losses caused by brackets, e.g. by using alternative materials, reducing...

Calculation method of EnEV The decision as to whether and how proof must be provided in accordance with EnEV depends, among other things, on whether a new building is to be erected or an existing building altered. EnEV 2014 implements the standards set out in the German Energy Savings Act (EnEG 2013), which the German Federal government revised in 2013 in order to implement the European Energy Performance of Buildings Directive (2010) in Germany. Among other things, this directive requires the member states to introduce the low-energy standard for new buildings in accordance with the following...

Wind load Wind load is one of the factors caused by climatic conditions, which has a variable effect on buildings. It results from the pressure distribution around a structure, which is subject to a wind flow. It generally acts as an area load perpendicular to the contact surface and is primarily a combination of pressure and suction. The slowing of the air current creates an overpressure on the frontal surfaces exposed to the wind. In the areas of the roof and side surfaces, the air current dissipates at the edges of the building creating an underpressure (suction) at these locations. An underpressure...

Anchoring base As well as the basic conditions stated above, the anchoring base available for anchoring the ventilated curtain wall, i.e. the material used in the construction of the supporting external wall, is also a key planning consideration. The selection of the type and number of anchors required depends on the load capacity and condition of the external wall. The lower the load capacity of the anchoring base, the more anchors and therefore brackets must be used in the substructure. The following diagram provides examples of a selection of commonly used anchoring base materials: Standard...