Talking Point

TALKING POINT WHAT THE ‘GOLDEN THREAD’ WILL MEAN FOR POWDER COATING

Richard Besant, Director of Powdertech (Corby), a specialist architectural powder coater, talks to PSBJ about how important it is that specifications are understood and adhered to throughout the entire supply chain, even more so now in light of the forthcoming Building Safety Bill.

Richard Besant is Director of Powdertech (Corby), a specialist architectural powder coater. Powdertech is a member of Council for Aluminium in Building (CAB) and Aluminium Federation (ALFED) and Richard is a member of the committee for EN 13438 – the European standard for powder coating on galvanised steel.

At Powdertech, we have spoken frequently about the importance of building specifications being established for all components at the outset of the project and adhered to throughout the supply chain.

Now, the latest Building Safety Bill, set to become law in 2022, has an objective to put in place enhanced regulatory regimes and accountability for building safety and construction products, and to ensure residents have a stronger voice in the system. At the heart of this more stringent regulatory regime lies the requirement to create and maintain a golden thread of information. The new bill recognises the importance of rigorous record keeping. The Building Regulations Advisory Committee (BRAC) has summarised as follows: “The golden thread is both the information that allows you to understand a building and the steps needed to keep both the building and people safe, now and in the future.”

Construction specifications will form part of the information required at each stage of the project to demonstrate that the building is compliant with applicable Building Regulations, and to identify and mitigate any risks of fire spread or structural collapse.

This is very good news, and particularly for powder coaters. Specifications for many building components are strictly defined and

rightly so. But for the final coating to the building envelope, be it powder coating, paint or anodising, we find that terms, such as ‘equal or equivalent to’, are often used. With this vague start point, problems begin to mount up as the components are moved down the supply chain. Since the building envelope is rarely made entirely by a single contractor, different elements from different sub-contractors end up at a variety of metal finishers, all using different pre-treatment processes and different makes of paint or powder.

‘Equal or equivalent to’ is a term that should be used with caution when one considers the critical issue of building safety with relation to fire. High-performance architectural powder coatings, such as those used by Powdertech, meet all current fire regulations, including Reaction to Fire Specification A2-s1, d0. However, ‘equal or equivalent’ not only relates to the product but also the method and control of application. Apart from the powder product itself which has its own characteristics of, notably, calorific value, the results of fire testing are dependent on applied coating thickness to the usual powder coating standard. Therefore, it is important that your specification includes reference to the need for application to be of a standard that ensures that the actual finish on a building meets the performance of those samples used in the regulated test facility.

Loose specifications can also cause serious delays in the build schedule as a result of confusion and discrepancies on different documents and different elements of the development. Orders or works instructions may disagree entirely with the original drawing annotations and time is wasted (at a point when time is in short supply) going back up through the specification chain to determine which is the actual finish required. Later, when new parts or repairs are needed, no one is clear as to the exact colour, shade or gloss level that has been used on various components. Serious delays to a refurbishment or extension project can occur whilst documentation is tracked down.

False economies can arise; the project brief may have specified a rigorouslytested aluminium system but left the coating poorly specified, resulting in the high-performance metal being coated with low-grade materials. The thousands of pounds spent on technically-advanced aluminium are squandered through using a coating that will not provide adequate long-term protection. In the worst cases, corroded elements will become a structural weak point, and time-consuming and costly repairs will be needed. A desire for short-term cost savings can result in smaller components, such as window cills and flashings, being finished to a lower quality. If these elements are peeling and corroding, within four to five years the building will begin to look unsightly and need maintenance, irrespective of the main cladding having a lifespan of over 25 years.

In the past, we have written that these issues, and others, indicate an urgent need for more rigorous specification of metal finishing at the start of a project, and strict record keeping by metal finishers on completion of the job. National Building Specification (NBS), the UK-based business providing construction specification information used by architects, engineers and other building professionals to describe the materials, standards and workmanship of a construction project, will be invaluable. Combined with building information modelling (BIM), input into the ‘golden thread’ required by the new bill is available and ready to access, and the new, stricter requirements should mean that coating specification is treated more seriously and becomes better defined. An approved metal finishing company can be selected to meet that specification across all elements of the building envelope, giving uniform quality and appearance of coating.

Metal finishers can do a lot to help this process by ensuring that they have their product and process details in BIM format ready to be uploaded as required. In this way, they can support their customers with regard to ‘the golden thread’. It is heartening to know that finally the construction industry will be moving forward to even better documentation and recording of the process and products that end up within and on the external face of every building we see. 

www.powdertechcorby.co.uk