Today’s construction projects have a lot to live up to. They need to come together quickly, meet strict quality standards and offer longevity, all while meeting exacting design specifications. To achieve this, every little detail must be carefully considered, including the fasteners and fixings that hold the building envelope together, according to Neil Kirwan, Specification Manager at SFS UK.
As with many things in life, well-planned projects minimise the chance for errors to occur during construction, which can be costly to rectify further down the line. Building envelopes, brackets and subframe systems need to be considered carefully in order to withstand whatever the elements throw at them. Fasteners and fixings – the very components that hold the fabric of a building together – can directly impact the performance, lifespan and thermal efficiency of the structure.
Despite this vital role, fasteners are not specified until Stage 4 in the RIBA plan of works. In many cases, they can often be the subject of ‘corner cutting’ – directly affecting the total cost of ownership and operation of the building. The same can be said for refurbishments and renovations of existing structures, whether due to a change in use, improvements in aesthetics or a need to improve their structural performance and thermal efficiency. With the right specification from the outset, these issues can be avoided, ensuring that the building envelope remains robust over the system’s service life.
Specifying the right components: five key principles
There are five principles of fasteners: durability, weathertightness, airtightness, aesthetics and structural performance. Failure of the fastener to satisfy these functions may lead to the inevitable, and sometimes catastrophic, failure of the system. The key is selecting the appropriate fastener and then ensuring that the specification is not deviated from.
There are a multitude of fasteners available on the market, each one designed for a particular use. These include self-drilling fasteners, self-coring fasteners, self-threading fasteners and clamping fasteners – all of which are specifically designed to simplify installation on site.
To avoid failure of a fastener or fixing component, the building function, environment, type of fastener and its material must be considered early on in the design phase. For example, when specifying components in coastal areas, due care and attention needs to be given to the humidity and corrosive salt-content in the air. Whilst surface coatings can be applied to prolong a fastener’s life, best practice is to use austenitic stainless steel fasteners in combination with galvanised steel purlins to avoid bi-metallic reactions.
Specification: An exact science
It isn’t just the external environment of a building that impacts how fasteners should be specified – the building’s use can have implications too. With product innovation and knowledge key to ensuring the right solution, suppliers should work alongside project managers to offer training and bespoke advice, from concept through to completion. This was certainly the case for Centre Parcs’ refurbishment of their Longleat Forest site, which houses a subtropical swimming pool and restaurant facilities.
To ensure the fastening system could withstand the chlorinated environment of the pool areas, SFS worked closely with the contractors and project engineers to specify TDA-S and TDB-S, R5 (EN 1.4547) grade stainless steel fasteners. Super austenitic R5 grade stainless steel fasteners were also specially developed for the project to provide added protection against stress corrosion.
While the internal and external environment are key to specifying the right product for the job, the lifecycle of the components and total cost of use must also be considered. As the old adage goes, if you buy cheap, you’ll buy twice – and this is almost certainly true of fasteners and fixings.
Specifiers also need to consider how building envelopes impact energy usage. As part of this process, there’s a need to identify areas where there are opportunities for reducing energy consumption, in line with Part L2 of the Building Regulations.
When refurbishing Shakespeare House in Hackney (see picture above), BPTW Architecture and Paneltec Services Ltd opted to install SFS’ NVELOPE NV1 vertical cladding system. In doing so, they were able to convert a low-quality housing block into a modern apartment building, complete with a contemporary feel and improved energy efficiency.
As well as being designed for concealed fix and structural bonding applications, the system is designed to allow expansion and contraction of the cladding when under strain from arduous weather conditions. Project Builder, SFS’ planning and design system, creates a bespoke solution, ensuring that the facade, fasteners and fixings are paired with the right brackets and subframe systems to offer installation and energy efficiencies.
Speed and efficiency, a winning combination
While the heat is on to increase the pace at which we construct new buildings, quality, thermal efficiency, sustainability and longevity must remain at the heart of the process.
Building envelopes, including the oft-neglected fastenings and fittings, must be considered much earlier in the plan of works, well thought out and properly specified, tapping into the latest technologies and product innovations. By embracing this much needed attention to detail, the industry can achieve the goal of faster construction and create buildings that are designed for the present but built and secured for the future.
For more about SFS, please visit www.sfsintec.co.uk.