Our nation’s architectural heritage needs preserving and we have an environmental and cultural responsibility to encourage the retention and reuse of existing buildings. When it comes to the repair of old masonry and preventing structural issues from occurring in listed or heritage structures, it’s crucial that the remediation work doesn’t alter the appearance and structural function of the building. John Heseltine, General Manager of the Helifix brand at Leviat investigates the masonry repair options available to engineers and specialist contractors working in the heritage sector.
Repairing masonry, whether in heritage or contemporary buildings, requires a thorough understanding of the existing construction’s form and condition. Accurately diagnosing the causes of structural defects is vital to ensuring the appropriate repairs are made. Without a proper assessment, repairs can be ineffective or even damaging to the original structure. In heritage buildings, repeated repairs are particularly undesirable due to the potential cumulative impact on the building. Thus, careful and methodical repair approaches are essential.
Early collaboration
Working with engineers that are skilled and experienced in masonry repairs at survey stage is one of the most critical considerations. Leviat with its in-house expertise, continuously works both alone and alongside external engineering consultancies to ensure the proposed repairs are appropriate and effective for the building in question.
Maintaining structural integrity
Repair solutions should specifically be designed to maintain the visual appearance of heritage buildings while effectively addressing underlying structural issues. Lightweight, high-grade stainless-steel products provide strength and flexibility without compromising the building’s original appearance. Helifix remedial solutions have been tested and refined over 40 years, proving successful in retaining the integrity of important buildings while providing the necessary structural support. The goal is always to deliver repairs that are as unobtrusive as possible, ensuring the structure is reinforced without accelerating the deterioration of original materials.
Repair methods for cracking and movement
Historic masonry buildings often face issues such as cracking or movement. A combination of products can address these problems, depending on the specific needs of the building. This may or may not include techniques outside of simply reinforcement of the building superstructure. Common methods include stitching cracks and tying masonry façades back to the core of the building. These interventions are typically much less visually invasive than traditional methods and tend to have shorter project timelines. The aim is to restore the structural integrity of the building while minimising the impact on its appearance and function.
Using lime mortars
Lime mortars are often preferred due to their compatibility with older building techniques and are ideal for re-pointing and re-bedding of masonry wherever possible. Unfortunately, the bond strength and compressive strength of ‘genuine’ lime products does not allow their use for many structural applications. In these cases, discreet modern materials avert concerns over changing the passage of water leading to freeze/thaw damage, while also avoiding the creation of rigid sections that could cause cracking.
Concealed products
One of the key advantages of modern repair solutions is their ability to provide structural support without being visible. By using concealed repair products, they will ensure that the aesthetic integrity of the heritage building is preserved. This approach minimises disruption to the original design while still providing effective structural reinforcement. Many of these repairs have proven to last for decades, with installations still effective 25 years after their completion. These concealed repair products are proven on many Grade I listed buildings and other significant structures across the world, providing long-lasting, environmentally friendly repairs.
Role of conservation professionals
Conservation professionals play a crucial role in ensuring that masonry repairs are compatible with a building’s original construction techniques and materials. These professionals must assess each building individually, taking into account its historical context, materials, and construction methods. Leviat works closely with conservation experts, offering advice and sharing its expertise to ensure that all repair methods and materials are appropriate for the specific needs of the structure. Additionally, the company provides educational opportunities, including a two-day residential course on masonry survey and diagnosis, which is aimed at both approved installers and industry professionals. This training is essential because only trained and approved installers can carry out the installation of Helifix remedial products, so that the repair works can be covered by a warranty.
Retention and reuse
There is growing recognition of the environmental benefits of retaining and reusing historic buildings. Preserving existing structures reduces the demand for new materials, significantly lowering the environmental costs of construction. The Helifix range of solutions has been at the forefront of this movement for over 40 years, providing repair schemes that extend the lifespan of heritage buildings while minimising waste. Their commitment to maintaining as much of the original structure as possible aligns with broader environmental goals and supports sustainability in the construction industry.
John Heseltine, Helifix General Manager said, “The preservation and repair of heritage buildings is a delicate process that requires a combination of skill, experience, and thoughtful consideration. By using modern, discreet repair solutions, the structural integrity and aesthetic value of these significant buildings can be maintained. Early collaboration with product manufacturers, engineers, conservation professionals, and a commitment to sustainability, ensures that appropriate methods are employed, which in turn supports both the conservation of our cultural heritage and environmental responsibility.”