Expected levels of performance

Wojciech Brozyna, managing director of Aluprof UK, questions the performance of installed systems to meet their specified performance.

As we specify architectural aluminium systems for many of our commercial buildings, and a growing number of new and improved residential dwellings, we often refer to a systems company specification for the weather performance of the product required. Often the weather rating of the product specified will be much higher than that required at the location but in some circumstances, given the location, the system or product will be expected to perform to its limits.

Given that each fabricator/installer will have a different production facility – fabricators at various levels of experience, with installers facing increased challenges on site – it is safe to assume that not all fenestration systems installed will meet the stated specification performance. While the industry, including Aluprof UK, is investing heavily in training of fabricators and installers, we cannot expect to have each installation to perform exactly as specified.

Let’s start with the fabrication of product: the more complex the design, the more likely shortcuts in fabrication will occur. For example, the application of sealant to weatherseal corners is crucial to meet high performance. However, some systems, such as stick curtain wall, are fabricated on site and not always in good weather, so we need to know that all the components are fitted with the correct sealant, under the correct weather conditions, before pressure plating and capping up.

The key here is for a main contractor to ensure that the fabricator/installer has the required knowledge, experience and training in the type of installation required; projects are often awarded on price and through fabricators that do not have the required experience.

While off-site production can be well controlled in a heated and well-lit factory space, conditions on site during installation can be quite the opposite. A few of the challenges that face the installer include: finding openings that are not square, dpcs in the wrong place, levels incorrect, and poor access. These issues all have a bearing on the product’s performance and often come under time retraints, as the contractor needs fenestration to be fitted to close off the building for following trades. All of which makes it difficult to make crucial changes in time.

The selection of system and advice from the specialist sub-contractor should also be discussed. For example, flush threshold French doors on a high-rise apartment block would need special consideration regarding weather ratings. Would a lift and slide door offer a better solution for a flush threshold condition as they carry an improved weather rating?

When we are aware that a system will likely be installed in a location that will test its performance, such as products used at height, it would be wise to take additional time in fabrication and installation to ensure everything is completed exactly to the manual. Systems company support should be requested in these areas to explore their experience of critical areas of fabrication and installation.

Over time, glazing gaskets and weatherseals can compress with a slight lowering of performance. Locking hardware will require adjustment to ensure adequate weatherseal compression. Should products be used in conditions near to their stated performance then routine maintenance should be undertaken to ensure product performance is maintained during the life of the product.

All the above issues fall within two areas of concern for Aluprof. The first being training and competence of the supply chain from system to installed product. Aluprof offers regular training courses for its customers to ensure quality of fabrication and understanding of the complete process through to installation. The second is the understanding of fabrication and installation parameters for the average fabricator. This allows for a better design to cater for some production and installation tolerances.

Understanding the issues of day-to-day tolerances also allows for crucial areas of fabrication to be explored and critical areas to be either highlighted or redesigned to reduce potential issues while maintaining the product’s performance.

It’s a cyclical process, and one Aluprof has long recognised as crucial to a product’s ongoing development and performance.