Air and watertight facades for Wonderwoods

In the bustling heart of Utrecht, construction is underway on Wonderwoods: two impressive residential towers by architecture firms Stefano Boeri Architetti and MVSA Architects that together form a vertical park. Although the towers differ in height and appearance, they have more in common than you might think. To ensure sophisticated air sealing, driving rain sealing and insulation, a uniform connection of the sandwich elements was sought, says Henny van der Heijden, product manager at Celdex. "Because the joint dimensions, details and sealing are largely identical, the applicator can process the precast seals for both towers even more efficiently."

Celdex was approached back in October 2020 by Bouwcombinatie Wonderwoods VOF (Kondor Wessels Amsterdam | Boele & van Eesteren), to exchange some ideas for the air and driving rain sealing. On this basis, the ball started rolling, says Van der Heijden. "Because we were already involved in the technical orientation phase, we were able to make adjustments where necessary to achieve the most optimal end result. For example, with regard to the joint dimensions. Moreover, on our advice, the structural engineer installed the anchors in a slightly different position so that they did not negatively affect the air seal. We then selected the right products within our Seal4Prefab sealing system." 

The 105-meter-high Boeri Tower will have a combined façade of wood frame elements (long façades) and precast sandwich concrete (short façades). And precast sandwich concrete has also been chosen for the 70-meter-high MVSA tower. "In both towers, Pre-Seal LF provides the air sealing and insulation on the inside, while EPDM Soft provides the driving rain sealing on the outside," said Van der Heijden. "In addition, Butyl tape 70S is used as a water barrier of
the sandwich elements." 

One challenge with the MVSA tower is the trapezoidal columns, beams and sandwich panels that give the building a unique aesthetic. "In particular, the underside of the beams affects the water barrier," said Van der Heijden. "To prevent flooding, we produced EPDM cellular rubber cuffs in four variants, which complete the overall sealing system." Finally, he points to the atriums and courtyards in the MVSA tower, in which there will be large pivot windows. "When these windows are opened in the summer, the interior facades turn into exterior facades. A special situation that requires thoughtful detailing and material choices, which we can provide perfectly. Because the complete prefabricated facades were worked out in 3D, we were able to assess all the details much better."   

https://celdex.nl/