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Welsh Slate helps give a Brussels apartment building façade a new buzz
Cwt-y-Bugail slate from Welsh Slate features on a revamped Brussels apartment building.
A former electric motor factory in Belgium is enjoying a new lease of life, and a facelift, thanks in part to Welsh Slate.
Some 88m2of Welsh Slate's Cwt-y-Bugail Dark Blue slate, with a honed finish on selected sides and faces, has been used to restore façade elements, wall copings and cills/thresholds at the La Magneto apartment building in Brussels.
Specified byDG Architectsand supplied by Welsh Slate Europe, the Welsh Slate elements were installed over the last seven months of a 10-year scheme by contractor Bajart. The façade was listed in 2017 due to its decorative elements in slate, installed vertically.
Built between the two World Wars, the site consists of several buildings constructed in different phases. The building whose façades on Rue Marconi were the subject of the restoration project was built in 1941, replacing old workers' houses.
Designed by architect Leon Guiannotte, the building features a late Art Deco style, the southern wing housing the administrative offices, while the northern part contained workshops. Industrial activity ceased in 1975 and the site was repurposed into housing. Today, it contains 20 spacious shared-ownership apartments.
DG Architects had been contacted in 2014 by the co-ownership due to issues with waterproofing and the stability of the cladding. At the time, the building was listed as a heritage site by the Brussels Region. Given its exceptional nature, particularly the widespread use of slate on the façade, DGA initiated a classification process which was finalised in 2017. This classification not only protected the building's architectural significance but also made it eligible for subsidies covering up to 40% of eligible costs. Simultaneously, DGA conducted a thorough analysis of the façades to identify defects.
Constructed of a concrete frame with brick cladding, a significant part of the building's historical architectural appeal comes from the use of slate in applications typically reserved for Belgian Blue Stone - thresholds, lintels, piers, pilasters and decorative cladding.
The façade covers approximately 800m², with the total budget for the restoration costing around €850,000, including scaffolding, plasterwork, brick cladding repairs, and the repair or replacement of slate elements.
The main challenge was to respect the original architectural choices and aesthetics while resolving technical issues related to the original slate installation. At the time, construction techniques for slate were often adaptations of those used for Belgian Blue Stone but due to the schistose structure of slate, some of these methods proved unsuitable over time, affecting its durability, particularly the use of iron fixings which have deteriorated.
DG Architects identified weaknesses and worked to develop technical solutions that honoured the building's history while ensuring long-term stability. These included new types of chemical anchors, eliminating joints along schistosity planes, correcting counter-slopes, and replacing drip edges with fine copper mouldings.
Floriane Frys, assistant to DG Architects' CEO Bertrand Dierckx and architect in charge of the Magneto project, said: "Our research and consultations led us to believe that the original slate likely came from the Martelange quarries, which were active on both the Belgian and Luxembourg sides during World War II. Since these mines are now closed, we launched an extensive consultation with various European slate quarries.
"Among the proposals received, Welsh Slate quickly stood out due to its strong resemblance to the original material. We were already familiar with Welsh Slate, having used its purple Penrhyn slate for roofing restorations, including at the Château de Freyr along the Meuse River, and the Abbey of Leffe. During our consultation, we discovered the Cwt-y-Bugail quarry and its extensive production of architectural elements, including façade cladding."
She added: "Besides its aesthetic qualities, which met our expectations, the quarry provided various national and European certifications guaranteeing the quality of its production. These theoretical results were further validated through strength and pull-out tests conducted by the contractor.
"Cwt-y-Bugail slate allowed us to preserve the existing structure while addressing technical challenges. Additionally, the commitment and active involvement of the quarry's management in this unique project helped convince us of our choice."
Floraine concluded: "The project's completion marks the end of a 10-year process. While this timeframe is not unusual for us as project managers, it was more challenging for the property owners who were not always aware of the numerous constraints involved in such a project. However, the final result has been unanimously praised from both an aesthetic and technical standpoint. The slate interventions are clearly visible yet respectful of the building's architectural principles, seamlessly integrating into its past and future history."
ENDS
Note to editors:Welsh Slate is the world's leading manufacturer of high-quality natural slate for a wide range of exterior and interior design applications including roofing, cladding, walling, paving, flooring, copings, countertops, hard landscaping and aggregates.
The company owns and operates the famous Penrhyn, Ffestiniog and Cwt-y-Bugail quarries in North Wales. Penrhyn Quarry has produced roofing slate since the 13th Century and has been the centre and focal point for UK natural stone for more than 700 years.
Welsh Slate is part of Breedon Group plc, a leading vertically-integrated construction materials group in Great Britain, Ireland and the United States.