Mark Snowden from Rockpanel outlines the benefits of ventilated facades, why their specification can help ensure the wellbeing of occupants and how substandard external cladding systems can lead to hidden costs and uninsurability
2017 marked a defining moment in the public’s consciousness regarding the fire safety of materials and systems used in the external cladding of new and renovated high-rise structures. It also brought into stark focus issues concerning compliance with and interpretation of fire and building regulations and how they impact on the materials originally specified for a project compared to what was, in reality, used.
In England, changes to fire regulations regarding residential buildings over 18 metres made it mandatory that all components in the external wall meet or exceed EN13501 Class A2-s1,d0, with guidance that those of 11 metres also adhere to the same specification.
Increasingly, the proposed use of some cladding systems, be they substandard in terms of fire-safety or inferior surface quality and shorter product life, can lead to difficulties in securing funding, issues with building insurance, future maintenance and replacement costs, impacting both residents and property owners.
What is a ventilated facade?
A ventilated facade is a construction with an air gap between the insulation and the cladding. It protects a building against the elements while at the same time helping maintain a healthy indoor climate. This type of external cladding offers many advantages. A ventilated facade is lighter and quicker to install than other options, leading to savings in construction costs and minimise disruption to residents. Individual panels can also be dismantled for maintenance and the whole facade can easily be replaced, reducing inconvenience to the building’s inhabitants.
Once in place, a ventilated facade reduces the direct solar impact on the building, resulting in a healthier indoor climate. It also offers thermal insulation, which contributes to energy efficiency and acts to reduce the impact of exterior noise on those within. Ventilated cladding also affords architects and specifiers opportunities to use colour and other surface designs to create facades not achievable with other alternatives. Realistic interpretations of wood, steel and stone are available along with RAL-matched colour and an ingenious design which changes colour depending on how light hits its surface.
The Euroclass system
Euroclass represents the most comprehensive and up-to-date standards system regarding reaction to fire. It compares ignitability, flame spread, heat release, smoke production and propensity for producing flaming droplets/particles etc. Within this system each classification means that, for a product tested within a certain end-use situation, specific parameters are achieved. For example, with relevance to an A2 rating, all of the tests for previous classification levels are completed, plus a test for the calorific content.
Considering the system as a whole
In order to be confident that a facade adheres to the highest fire safety performance, it is vital to view the characteristics of its construction as a whole – from panels and sub-frame, through to the insulation used and the design of cavity compartmentation, fire barriers, fixings and all other components.
Arriving at an agreed solution
Ideally, with any recladding project, a feasibility programme is instigated to explore design options and to consult with stakeholders, residents and other interested parties to arrive at a jointly agreed solution. A resident committee member commented about one of the projects depicted here: “The consultation process was very democratic. Regular meetings were held to discuss the plans and progress with due diligence given to every aspect of the materials and installation. We are very pleased with the results and know surrounding residents are envious, with some assuming the three blocks are complete new builds.”
In relation to this project, residents were shown examples of the proposed materials, with tenants and landlords able to visit an on-site space where they could view samples, gather information and build confidence in the renovation scheme. Tenant and council meetings were also held where the fire resistant properties of the proposed materials were demonstrated.
Two projects where sustainable and non-combustible ventilated facades have been used to great effect in the complete recladding of residential blocks, a development of three in London and a similar grouping in Manchester, delivering future-proof transformation for the hundreds of homes within.
Planning approval for The Manchester project was made considerably easier due to the wide range of surface designs available, enabling close matching of the cladding to be replaced.
For the London properties, the panels have a unique appearance which reflects in such a way that, depending on the angle light hits its surface and the point of view, a changing spectrum of colour tones are visible. Due to an innovative and unique crystal effect layer, it transforms any building into an eye-catching structure that is constantly transforming, impactful and inspiring.
Mark Snowden is business manager for the UK and Ireland at Rockpanel