Behind the secret fix

Panel Systems unravels how recent technological advancements became the catalyst for uninterrupted exteriors, and where this trend is heading.

Newness has always attracted the eye, which is why buildings are often designed with a contemporary aesthetic. There is an assumption that contemporary buildings are more attractive and therefore perceived as more valuable by clients, tenants or investors. It is one of the reasons why modern panel systems that create sheer, smooth facades have grown in popularity in recent years. The introduction of modern finishes such as painted glass, lacquers and patinations have all accentuated this aesthetic, creating buildings where people want to live and work.

Across the UK, an increasing number of buildings are sporting facades and exteriors that are unhindered by fixings. These sheer facades have been made possible due to innovation in concealed fixing systems, or what is more commonly known as ‘secret fix’ methods. These methods of fixing panels to the exterior of a building in a discrete way are becoming increasingly popular due to the contemporary trends in architecture.

Types of fix

There are a number of different secret fix methods, but deciding on the actual system that is suitable depends on the facade and material. Firstly, mechanical secret fix methods consist of a rigid aluminium rail system behind the panels, which is anchored to the main structure of the building. This means individual panels can be ‘hung’ from this system, with advances in manufacturing allowing this to be done via recessed holes machined to the rear of the panels. This type of fixing allows individual panels to be removed, providing access to services located behind. Many clients prefer this because it can be cheaper and less disruptive compared to having to access services from the inside of an already occupied building.

An alternative to a secret fix system for those looking to achieve that ‘sheer’ aesthetic is an adhesive fix method.

That method is more cost effective than mechanical secret fix and involves primers and adhesives being applied to a timber or aluminium framing system. Despite being a cost effective alternative, it doesn’t allow individual panels to be removed, unlike the secret fix approach. There are further limitations, as the adhesive can often only be used within temperatures ranges of 5°C to 35°C and there are also restrictions on air humidity, of up to 75 per cent. Conversely, mechanical secret fix can
be considered a modern method of construction as it can be fitted in a wider range of site conditions.

Recently, a mechanical secret fix system enabled a seamless facade to be created for a hospital on the south coast of England. The specified cladding material was supplied with profiled horizontal edges that were fitted onto continuous aluminium rails.

The panel edges were designed to mask the aluminium profiles used to install the panels, as part of enhancing the aesthetics of the building. The secret fix system used was ideally suited to projects where quick installation of large, uninterrupted facade surfaces was required. There was also a range of specialist fixing systems to support other types of facade material that create the same contemporary seamless aesthetic.

Accentuating exterior features

Sometimes seamless facades are not required, for example, where the designer wishes to make a feature of shadow lines or accentuate an elongated aspect. In these instances, face fix, also known as through fix or visible fix, can be used. The panels in this type of installation are usually attached to a timber batten
or aluminium rails using screws or rivets. On many exteriors, this is a perfectly adequate fixing method; the only time when it wouldn’t be suitable is when an uninterrupted aesthetic is required.

As the trend towards sheer, smooth facades looks set to continue, what does this mean for cladding specification? Traditionally, only selected cladding materials could be used to achieve this effect – such as aluminium or glass. However, innovation in fixing systems means that seamless facades are possible with an ever increasing range of materials. When these are specified in the form of a composite panel, it meets the requirements of modern methods while reducing installation times on site. It is anticipated that the demand for sheer facades would continue to drive innovation in secret fix methods, opening up even more opportunities for the contemporary buildings of the future.