Ardit Strica of Onduline Building Products discusses the challenges faced in heritage roofing projects and offers insights into selecting appropriate materials and techniques that meet both conservation and performance requirements
Restoring heritage buildings is a meticulous process that requires a deep understanding of both the historical significance of the structures and the modern standards that must be met. Contractors working on these projects are faced with the challenge of preserving the aesthetic integrity of heritage sites while ensuring that the buildings are safe, functional, and compliant with modern building standards.
One of the primary concerns in heritage roofing projects is the selection of materials that align with the original appearance of the building while providing the necessary durability and performance required. While traditional materials such as slate, clay, and wood have a timeless appeal, they may no longer be practical for modern roofing demands. For example, original materials might be unavailable, too costly, or lack the durability required to withstand modern-day conditions.
In addition to material selection, contractors must consider the structural integrity of older buildings. Many heritage buildings were constructed without the modern reinforcements we take for granted today. Therefore, adding new roofing materials that are significantly heavier than the original ones could compromise the building’s structural stability. This means that any solution implemented must not only preserve the visual appeal but also respect the load-bearing limitations of the existing structure.
The aesthetic value of a heritage site is often tied to its roofing. The rooflines, tiles, and overall roofing design contribute significantly to the building’s character. When restoring or replacing a roof, it is crucial to replicate these elements as closely as possible to maintain the historical authenticity of the site. However, modern performance standards require that the roof also provides adequate protection against weather, insulation, and ventilation, which older roofing systems were not necessarily designed to handle.
Innovative solutions
To address these challenges, innovative materials and techniques have been developed to meet both conservation and performance goals. Lightweight composite materials, for instance, can mimic the appearance of traditional roofing materials such as slate or clay tiles while offering enhanced durability and reduced weight. These materials are often designed to meet modern standards of insulation, waterproofing, and fire resistance, thus ensuring that the restored roof performs well without compromising the building’s structural integrity.
Furthermore, incorporating technology in the planning phase, such as 3D modelling and thermal imaging, can further aid in achieving precise and efficient installations. These tools help in assessing the building’s needs and simulating the impact of different materials and techniques, ultimately supporting a decision-making process that honours both the heritage and functionality of the site.
Another approach that is gaining popularity is the integration of sub-roof systems, which provide a multitude of benefits without compromising the historical appearance of the building.
Sub-roof systems are installed beneath the primary roofing materials, playing a critical role in enhancing the durability, energy efficiency, and weather resistance of a heritage building’s roof. By adding an additional layer of protection, sub-roof systems help to manage moisture, prevent leaks, and improve insulation, all while remaining invisible from the exterior. This makes them particularly valuable in heritage projects where maintaining the original look is paramount.
Sub-roof systems are particularly beneficial in heritage projects because they allow for the use of any roof tile, new or old while offering complete watertightness, enhanced protection and durability.
The systems are designed to work beneath any type of roof tile, providing a watertight barrier that safeguards the building without altering its external appearance. Contractors can maintain the original look of the roof by using the same style of tiles or slates that were initially installed, while the sub-roof system ensures that the building meets modern performance standards. This means that the visual integrity of the building is preserved, while the roof benefits from the additional strength and resilience that comes with contemporary roofing technology.
Restoring the roof of a heritage building is a delicate balance between preserving the past and embracing the future. By marrying traditional craftsmanship with advanced materials and techniques, contractors can ensure that restored roofs not only meet modern performance standards but also support the preservation of the building’s historical and architectural value.
Ardit Strica is technical manager at Onduline Building Products