With 17 years in the roofing and cladding industry, Stuart Brown has been closely involved with the technical development of a number of roofing systems at CA Group, as well as playing an integral role in the evolution of company’s cur ved roof design.

building, at all stages of its lifecycle, presents a number of risks, from the initial design and installation through to completion, use and ultimate disposal. Having a prescriptive specification, when a contract is tendered, not only gives the client more certainty about the integrity and expected performance of the end product, but it also provides an invaluable layer of accountability on the part of the specification provider, who is clearly stating that, providing the specification is met, the job will be fit for purpose.

In recent years, budget constraints have led to an increase in some main contractors encouraging roofing and cladding suppliers to break specifications to such a degree, that the resulting development no longer bears any resemblance to the original recommended guidance and the liability for a building’s eventual failure no longer sits with the supplier but with the investor, developer and tenant.

When the cladding contractor or main contractor chooses to change a specification and install replacement components, it is incumbent on them to test the alternative system in full. If the system has not been tested it must be deemed fragile. Sending workmen to carry out inspections on a fragile roof is irresponsible and puts them at risk of injury or even fatality.

In addition to the system itself any proprietary system, such as a Horizontal Life Line (HLL) fitted on to the roof, must also be tested as a complete assembly to ensure that, in the event of a fall, the structure is capable of absorbing the additional force, which can be significant. Testing on the external sheet alone does not prove compliance.

In the event of an incident, each link in the supply chain will be examined to ensure that every effort was made to follow best practice. The client, architect and main contractor should be able to demonstrate that they have taken adequate care to deliver and install a Non-Fragile design. Allowing a cladding contractor to install an untested assembly of components is dangerous and leaves the entire team at risk of prosecution.

It is also important to note that the profiler or panel supplier cannot claim Non-Fragility on a singular component. Neither can companies that make rooflights, for example, claim that their product, in isolation, is Non-Fragile, as it is only the installed assembly, including the profiles, rooflights, fasteners and sealants, when tested as a whole, that can be deemed Non-Fragile – providing it passes the necessary tests.

This is particularly relevant with the significant uptake in roof mounted PV installations which have added another layer of complexity in terms of the impact on the roof’s integrity, and the resulting health and safety implications for anyone accessing the roof to meet the necessary maintenance requirements.

Tests for Non-Fragility are more important than ever to ensure the safety and wellbeing of roof operatives. This is not just a requirement during the installation of the PV array, but must last for the entirety of the asset. Roof system guarantees and Non-Fragility periods go hand-in-hand. As such, if the roof system guarantee is compromised, the roof assembly must be regarded as fragile.

Guarantees

Breaking with specification may also have an impact on the validity of the overall guarantee. Often it is only when something goes wrong and a claim is made, and then rejected, that the building owner becomes aware of the fact. Essentially, because the components chosen were not the components specified on the original project, the system in its entirety is no longer covered by the terms of the original guarantee.

Instead, the claim must be made against the individual manufacturers of the different component parts, each of whom must arrange coordinated site visits to examine the cause of the problem. Of course, the likelihood in this situation is that the individual manufacturers involved will be reluctant to accept responsibility and will try to shift the blame onto someone else for the failure, making the situation very difficult to resolve. Using a system with all components supplied from a single manufacturer eliminates this potential issue.

Breaking with specification can also have performance implications, specifically in relation to acoustics, thermal performance, solar gain and natural light. It is therefore essential, when substituting components, that the amended specification is put into the building’s calculations, such as SBEM, in order to be able to accurately predict the building’s future performance.

When an item has been specified as part of a system it has already been tested and as such is covered by a guarantee. If the item does not perform it will be put right. If it has been substituted, the responsibility no longer lies with the specifier but with the cladding contractor.

The specification provides essential guidance to the design team in terms of the materials and workmanship required for a specific development, backed by a robust guarantee. In the worst case scenario, by breaking with specification, main contractors are buying in to sub-standard practices hidden by worthless guarantees and warranties, which could ultimately put lives in danger.