Case study – Structural UV Relining of Victorian Brick Culvert Beneath Canal
McBreen Enviro UK was contracted to clean and fully reline a 750-800mm Victorian brick culvert beneath a canal, delivering a technically complex rehabilitation project.
The works involved extensive culvert cleaning, access and enabling preparations, a detailed laser survey, pre- and post-installation CCTV inspections, installation of a structural UV-cured liner, and precision grouting to ensure full contact with the existing brickwork.
Challenges:
• Canal crossing: The culvert runs directly beneath a canal, requiring careful coordination of access and installation works.
• Restricted access: Specialist equipment and materials had to be safely mobilised within a controlled site compound.
• Busy location: The site was adjacent to a main road, requiring traffic management and careful planning of site logistics.
The McBreen Solution
The project began with Jet-Vac cleaning, a detailed laser survey, and CCTV inspection to accurately map the culvert’s interior and prepare it for rehabilitation.
McBreen Enviro UK then mobilised a UV installation unit, a 5-ton winch, and a team of six trained engineers to carry out the relining works.
The installation of an Impreg GL16 UV liner (DN900, 10.1mm thick, 62m long) required careful coordination to overcome access challenges beneath the canal and alongside a busy road, ensuring a safe and precise installation.
A 750mm diameter UV-cured liner, 10mm thick, and 41 metres in length was installed using a glide foil system before being UV cured to form a new structural lining within the existing brick culvert.
Following installation, grouting was carried out where required to seal any voids between the liner and the host structure, ensuring full contact, improving hydraulic performance, and extending the asset’s expected service life by over 100 years.
A post-installation CCTV survey was completed to verify the integrity of the installation.
Result
The works resulted in the successful structural rehabilitation of the culvert along its full length, providing a durable lining solution within the existing brick structure.
The approach minimised disruption to the canal and surrounding habitats, protecting local wildlife and maintaining the integrity of the waterway.
Controlled site access and careful planning also reduced impacts on the local community and road users, while the structurally reinforced culvert ensures long-term operational reliability.
In addition, the improved canal area now supports safe, accessible walking paths for local residents, enhancing community enjoyment of the space.
