Feature
Continued from p35
procurement could affect how individual components interact once installed.
Whole-roof compatibility becomes key consideration
Scott said contractors and developers should consider how products work together rather than assessing compliance on an individual component basis.
“ The question shouldn’ t simply be,‘ Does this individual product comply?’” he explains.“ It should also be,‘ Has this combination of products actually been designed and tested to work together?’
“ A roof is exposed to wind, rain, snow, temperature fluctuations and increasingly extreme weather throughout its life. If components haven’ t been developed as part of the same system, you are introducing an unknown into that performance.”
The performance of a roof is dependent on multiple components working together, rather than individual products operating in isolation.
This can become particularly relevant when contractors are asked to identify savings after a roof specification has already been prepared.
Changing one component can potentially affect the interface between products, including the way tiles, fixings, underlays, ridge systems, hip systems, verge components and ventilation products fit together.
The issue can also extend to product guarantees.
Russell Roof Tiles warns that using third-party components alongside its tile ranges without adequate test certification could affect roof system performance and potentially the guarantees available on the completed system.
The manufacturer says material selection should also be considered when assessing Dry Fix components.
Factors including UV stability, structural integrity and weather resistance can affect how components perform during their service life.
Russell Roof Tiles uses PVC within its systems and says the material has a track record of more than 30 years on UK sites, with durability and resistance to UV degradation among its characteristics.
Solar PV adds to roof system considerations
Fire performance is another consideration highlighted by Russell Roof Tiles as the installation of solar PV systems on roofs becomes more widespread.
The increasing presence of rooftop solar technology means the performance of the roof needs to be considered as an integrated assembly rather than a collection of separate products.
For housebuilders, contractors and developers, this places greater emphasis on ensuring that components specified for a roof are compatible and appropriate for the particular construction.
A complete system gives contractors and developers greater clarity.”
The wider roof build-up can include multiple products supplied by different manufacturers, making the relationship between individual components an important part of the specification process.
Russell Roof Tiles argues that the focus should therefore be on the performance of the completed roof rather than simply whether each individual product meets its minimum requirements.
RussSpec brings roofing components together
Russell Roof Tiles has developed its RussSpec approach around a wholesystem specification.
The specification brings together concrete roof tiles with the underlay, fixings and ventilation products required for a project, with the components selected to integrate as a complete roof solution.
The company’ s technical team develops specifications based on factors including the location of the building and its construction requirements.
Additional support can include site verification, training and compliance inspections.
RussSpec also provides a 15-year Design Liability Guarantee covering the integrated roof system rather than individual roof tiles.
For Scott, having responsibility for the specification held by a single manufacturer can be particularly relevant if problems arise after construction.
“ With a roof assembled from products that have not been properly evaluated, supplied by several different businesses, establishing where responsibility sits can become complicated very quickly,” he says.
“ A complete system gives contractors and developers greater clarity. There is one specification, one manufacturer and one point of responsibility rather than several suppliers potentially looking at each other.”
Value engineering should not compromise roof performance
The issue of product substitution is likely to remain relevant while construction costs continue to put pressure on project budgets.
For roofing contractors and specifiers, the initial cost of an individual component is only one part of the overall assessment. Compatibility, installation, performance and the potential consequences of future failure can all affect the cost of a roof over its service life.
Russell Roof Tiles says proposed substitutions should therefore be assessed carefully to establish whether the alternative component is suitable for the wider roof system and whether it has been tested in combination with the other products being specified.
The manufacturer argues that the cheapest individual component does not necessarily represent the lowest-cost option if its use introduces uncertainty around compatibility or performance.
Its own Dry Fix products are manufactured and tested to British and European Roofing Standards, while the company continues to invest in production technology, automated manufacturing and quality control.
For projects where multiple roofing components are being specified or substituted, the central consideration remains how those products perform as a complete roof assembly rather than in isolation.
36 Issue 26 | 2026