Breaking Bad: The Importance of Sticking to Specified Products

If you work on any construction project, you will notice certain manufacturers’ brands. Whether it is for insulation, lintels, bricks or thermostatic radiator valves, there is a reason why they are there; it has not happened by chance.


Following stringent verification, these brands have been specified because they meet the precise requirements of a particular job. Most likely, they have been extensively and successfully tried and tested on previous projects.

Tom Merton, Technical Specialist at Armacell – a worldwide leading manufacturer of flexible equipment insulation material and engineered foams – explains why it is important that contractors deployed across all areas of building projects – and not only those working within HVAC – honour original product specifications and do not pass off alternative products in their place.

The majority of architects and specifiers usually know which brand they want to use on a project. As they base their choice on specific knowledge, technical performance, past experience and client requirements, it is vital that contractors honour their decisions, both at the stage of initial construction and ongoing building maintenance and repair.

In the case of HVAC systems, in particular, critical elements such as pipework insulation can have a make-or-break effect. An installer who decides to replace a specified product with insulation of their own choice needs to be aware of the risks involved. Changes made during the installation process can be expensive and time-consuming to put right or repair. In the worst-case scenario, the consequences may include loss of reputation, call-back or litigation further down the line. Put simply, sticking with the original specification reduces risk in the long term.

According to the National Building Specification (NBS) technology platform, 70% of respondents to a recent specification survey agreed that product substitution is still a real issue in the industry. It goes on to say that this occurs for a variety of reasons, the main one being cost pressures. Decisions to substitute products are often made without considering the consequences the substitution can have on the building’s performance and lifetime costs.

Non-compliance with a specification through the use of an inferior product rarely benefits the installer, increases warranty risks, and may significantly impact the building’s ongoing maintenance and operational costs. While in many ways it is up to the specifier and client or developer to ensure that specifications are not broken on site, that does not release the installer from the responsibility of taking such consequences into account, and where possible, advising the customer accordingly.

During the past 55 years of supplying some of the UK’s biggest and best-known technical insulation projects, Armacell has become aware of cases where installers have substituted closed-cell insulation for open-cell versions. The outcome was costly remedial work for the installers in question after the site had been handed over. Closed-cell insulation is specified for a reason: it prevents condensation along pipework and fittings, thus stopping moisture intrusion and loss of thermal efficiency. The findings of recent research conducted by the Fraunhofer Institute for Building Physics in Stuttgart, Germany, showed that over a period of 10 years, the thermal conductivity of Armacell’s own closed-cell flexible elastomeric foam (FEF) insulation, AF/ArmaFlex Class 0, rose by only around 15%, while over the same period, that of open-cell mineral wool rose by 77% and polyurethane (PUR) by 150%.

Things, however, are starting to change. For example, Armacell’s installer training course helps reinforce the need to keep to the original specification. Whilst making installers aware of the benefits of working to specification, this course also highlights some of the dangers and costs of failing to do so. Recent updates to our training programme have also made it more relevant to the needs of the market. Likewise, our building information modelling (BIM) objects help support a more robust specification process along the lines of “change one thing, and you change the whole building”.

Specifications are created for a reason. Ultimately, they safeguard an HVAC installer or any other type of contractor against comebacks after a site has been handed over. When it comes to specifying most building products, it is not only architects and designers who should consult manufacturers’ dedicated specification teams for guidance through the process. Installers need to do so too, in order to understand why products have been specified for a reason, and substitutions may result in an unnecessary risk for everyone.

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