Background
The 100+ bedroomed Cosmopolitan Hotel in Leeds centre was built in 1890. Located on the corner of Lower Briggate and Swinegate, it has undergone a multi-million pound renovation and is ready for reopening in Spring 2025 as an IHG Hotel Indigo property owned by Belfont Hotels and managed by Countrywide Hotels. NRA Roofing Ltd was engaged by Clegg Construction to remove and replace the hotel’s existing roof.
Roofing product choice:
The new roof was created using a breather membrane from Permavent, graded Premium Gold roofing battens from SR Timber, and premium-grade Spanish Slate SIGA 112s for durability and aesthetics from SIG Roofing.
High-quality lead sheeting, building paper, copper components, and robust fixings were also required for the new roof and the specification service offered by AccuRoof, part of SIG Roofing, assisted with the selection of the roofing products, which were supplied by the Old School Yard, SIG Roofing Branch in Leeds.
The SIGA 112s Spanish slate supplied by SIG Roofing was sourced from the Leon Region of Spain. Before placing the order, the team from NRA Roofing visited the quarry and factory in Spain with SIG Roofing to verify the production processes, quality, and availability required for this prestigious large-scale project. SIGA 112s is a smooth, dark blue/grey slate available in two thicknesses 5mm and 7mm, and numerous sizes. Due to its similarity to slates produced in the Vale of Ffestiniog, the SIGA 112s has been awarded Snowdonia National Park approval. It is a versatile slate suitable for products nationwide and comes with a 75-year warranty.
SIG Roofing also supplied SR Timber PREMIUM GOLD® Roofing Battens for the project. This product meets the specifications outlined in BS 8417:2011+A1:2014 (preservation of timber) and is graded according to BS 5534:2014+A2:2018.
More details on the SIGA slate products at https://www.sigaslate.co.uk/ and SR Timber batten at https://sr-timber.co.uk/
Installation challenges:
The project presented some unique challenges, including minimising disruption to the ongoing operation of the hotel, which remained open during the works. Many of the original features on the building had deteriorated over time, necessitating careful restoration work or replacement. This meant that the most suitable methods and materials had to be identified, ensuring both durability and compliance with historical accuracy and current legislation.
Given the unique challenges and historical significance of the structure, the work required adherence to local conservation guidelines to retain the buildings character, whilst integrating modern weatherproofing solutions.
The most striking and challenging feature was the curved slating on the front elevation. Curved slating is an intricate and labour-intensive task. The Yorkshire-based slaters from NRA Roofing approached the task with dedication, leveraging extensive experience to produce a stunning architectural feature. This involved careful planning with string lines (both horizontal and vertical), precise grading and sorting of slates, adjusting batten spacing, and shaping each slate to recreate and modernise this spectacular design element. They also expertly installed code 4, 5, 6 and 7 lead across a variety of features including flashings, cills, bays, and gutters.
Located in the city centre, the site posed significant logistical challenges too, due to limited space and strict loading restrictions which demanded detailed planning and close collaboration by site management.
Despite numerous challenges, the results preserved historical integrity and the total reroof took just three months to complete.
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