The complexity of façade projects is constantly increasing to achieve ever more stringent performance targets and ambitious designs – often using innovative materials and components that may not have been deployed widely in the market.
The result is that buildings are becoming more technically demanding with enhanced fire safety needing to be balanced with higher thermal performance, all within the context of a net zero construction approach. None of this complexity affords the design and construction teams more time, however. Programme pressures continue to apply, with the added challenge of the labour and skills shortages faced by the sector more widely.
For many architects, façade designers and building envelope contractors, the solution has been to shift to systems rather than specifying individual components to form completely bespoke designs. That is evident in the growing appeal of system approaches to all kinds of building applications, from curtain walling and entrance doors to HVAC systems and internal partitions.
Reducing risk when adopting a system approach does require careful consideration to check they have been designed, tested and supported from the outset as a complete solution. But it also requires a focus on the individual components that make up the system. In rainscreen or rear ventilated façade construction, this is particularly important for the substructure framing and associated fixings – an assembly which is hidden from view but fundamental to a façade’s structural integrity and performance.
MINIMISING RISK AT EVERY INTERFACE The substructure of a rear ventilated façade forms the cavity needed to accommodate insulation and allow sufficient airflow and drainage. It is subjected to a variety of forces, not least those resulting from strong winds and building movement, as well as the weight of the panels that form the external cladding.
A combination of components is needed to form the substructure, often sourced from multiple manufacturers, including rails, brackets, fixings, thermal isolators, insulation anchors and fasteners to hold the frame together. For the substructure to provide complete confidence, evidence of verified compatibility should be provided for each of these interfaces and it must be clear who is responsible if something fails to perform as expected.
Even though individual components may be backed with evidence of their performance, will they achieve this in a complete assembly? Are the tolerances compatible and have movement allowances been considered? Gathering all this evidence and information where a mixed system approach is used can be time-consuming because it needs more coordination and verification, but it is an essential part of the process.
WHY COMPLETE SYSTEMS SIMPLIFY SPECIFICATION One of the reasons EJOT CROSSFIX was developed was to help streamline the design and specification process for facades. It is supported with robust test data and evidence of performance across a wide range of designs, building substrates and cladding materials through its comprehensive European Technical Assessment (ETA). The system has been widely used in façade projects across Europe and now the UK.
With CROSSFIX, every component has been designed to work together. The system brings a single-supply source to the table, streamlining lines of communication and the simplicity of having a single point of contact at EJOT UK throughout the project. As a result, the feasibility and compatibility of the system can be established early, saving time and cost.
EJOT UK can provide performance data relating to the assembled system as well as isolated components. That can offer clear insights into a proposed substructure’s structural performance, load transfer, thermal performance and durability. It also means EJOT can offer a single source of technical information based on one technical manual and design methodology for multiple components, backed by one source of calculations and one source of updates – reducing the potential for conflicting information which can occur when using multiple suppliers.
CONFIDENCE THROUGH SPECIALIST ENGINEERING SUPPORT
A key advantage of partnering with EJOT UK for the façade substructure is having the support of the team that engineered it, who have in-depth knowledge of its capabilities and limits. This is particularly so for EJOT CROSSFIX, which has a team of product designers and engineers supported by UK-based technical consultants who can get involved in projects early to help architects achieve the optimum design. components, tolerances, fixing capacities and movement allowances. As an integrated system, all these factors within the CROSSFIX assembly have already been considered and validated.
PROVIDING CONFIDENCE ACROSS THE PROJECT TEAM
Choosing a complete system like CROSSFIX from a single manufacturer can simplify design coordination, reduce the number of interfaces requiring verification and provide a clearer line of technical support. If you are an architect, that can make the specification process more efficient while offering greater confidence in system compatibility for a project, all with the advantage of being able to access specialist technical support from a UK team as and when required.
Structural engineers benefit too through the information we are able to provide about load paths, tested performance data and engineering calculations. This enables engineers to more easily verify that the supporting structure is adequate, design appropriate fixings and interfaces, as well as identify and manage critical load transfer points. The end result is reduced risk of unexpected structural behaviour or overloading.
Developers benefit because the technical risk is reduced and fewer design changes will be required – this can help to keep the project on track, reduce delays and cost, ultimately achieving better programme certainty. Given the test evidence that supports CROSSFIX, developers also benefit from assurance on operational energy costs, fire compliance requirements and overall ESG performance, all of which can contribute to increasing the value and attractiveness of a completed development.
For façade contractors, using a complete system like CROSSFIX simplifies procurement, given that they only have to deal with one supplier for the whole substructure. But the system also helps to deliver a quality façade project with greater confidence because it can be used with both horizontal and vertical support profiles and with fixed or sliding points, giving installers the flexibility to adapt more easily to site conditions and façade configurations without requiring multiple specialist components.
No manufacturer or system can eliminate every project variable, of course. But partnering with EJOT UK can help to reduce technical uncertainty at key project interfaces before construction begins. That can have significant value to the project overall, enabling project teams to make more informed decisions and deliver façades with greater confidence. www.ejot.co.uk/CROSSFIX
Our team can advise on the most suitable bracket selection to support the system, movement joints and how to accommodate the calculated loadings. This determines the fixing arrangements, but also means we are ideally placed to help provide input into the façade design and advise on installation sequencing.
FEWER ASSUMPTIONS As an ETA-backed system, CROSSFIX enables façade design and installation to be completed with fewer assumptions. This is partly due to the technical support available from EJOT UK, but is also a reflection on the comprehensive scope of the ETA and its independent verification process. As every assumption introduces potential risk into the façade substructure, choosing CROSSFIX means greater certainty regarding compatibility of interconnecting