Firestone Building Products - The optimal watertight roofing system

The striking Les Trèfles building in Anderlecht, Belgium, opened its doors in 2017. This school and sports complex has room for 750 pupils, and also serves as a popular location for sports clubs and associations. Brussels-based ÁRTER Architects received an Exemplary Building (BATEX) prize from Brussels Environment for the design of this remarkable building, which is an innovative combination of passive construction, sustainability, learning and eco-friendly features.

MUTEC, Firestone Building Products' master contractor, was responsible for waterproofing the roof with the UltraPly TPO thermoplastic polyolefin membrane, which had an eye-catching green roof installed on top of it. The company has a great deal of expertise and experience in TPO waterproofing and green roofs.

The structure of Les Trèfles resembles a four-leaf clover, referencing the French word for clover, trèfle. However, while a four-leaf clover is known as a lucky charm, nothing was left to chance when it came to waterproofing. This is why the client chose Firestone's UltraPly TPO roofing system.

High-quality roofs

MUTEC, a Belgian market leader that specialises in the installation of Firestone UltraPly TPO roofing systems, has been owned by the Willy Naessens Group since 2013. This industrial roofing company primarily focuses on the B2B market for waterproofing industrial buildings in new-build and extensive roof renovations. Every year, approximately 325,000m² of roofs are sealed by MUTEC.

"On top of our great expertise in TPO, we also work daily with PVC, EPDM rubber and bitumen membranes," explains Vincent de Meyer, MUTEC's managing director and founder. "We are a 'Firestone Master Contractor' and are, therefore, certified to install Firestone products. This is a status that you have to earn and we are very proud of it. We run continuous training and seminars to keep our employees up to date with the latest developments, installation techniques and technological evolutions," adds De Meyer.

The roof surface of Les Trèfles, which measures around 7,000m², was fitted with an adhered build-up roof consisting of:

  • a self-adhesive bitumen vapour barrier membrane that was also used to cover all the upstands
  • two layers of 15cm-thick polyisocyanurate insulation boards, that were fully adhered with a two-component polyurethane adhesive
  • 1.5mm-thick Firestone UltraPly TPO single-ply membrane that was fully adhered with contact adhesive.

"The roof also features 90 ventilation openings (two per classroom), which had to be air and watertight at the vapour-barrier, as well as the roof level," says De Meyer.

The choice of roofing membrane, plus all other construction materials, was determined based on a life-cycle assessment, which takes into consideration the environmental impact products have during their lifetime. The green roof did not just consist on sedum vegetation: a wide variety of species, such as succulents, flowers and herbs were chosen as well. Green roofs were also installed on the four sloping sides of the sports hall roof, but only succulents on pre-cultivated sedum vegetation mats were used because the roof structure had a lower bearing capacity there.

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Firestone Building Products EMEA
Ikaroslaan 75 1930 Zaventem
Tel: +32 2 711 44 50 Fax: +32 2 721 27 18
Contact: Firestone Building Products Europe

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