Smart sealing at high altitude

The Ensemble Amsterdam

The skyline of Amsterdam-Zuidoost is getting a major upgrade with The Ensemble, an iconic high-rise project in Amstel III. Once a monotonous office landscape, it is increasingly turning into a lively urban district with homes, offices and amenities. The Ensemble plays a key role in this: two towers of 120 and 100 meters high will offer space for 592 rental apartments, 19,000 m² of office space and various stores.

Building at high altitude presents serious challenges. How do you ensure that wind and driving rain do not get a grip on the facades? Celdex's specialized sealing products ensure that this imposing building can withstand weather and wind without slowing down construction. The two towers go up at the same time, each using a different construction method. The tallest tower (120 meters) will have a façade finish with wood frame elements, where the second tower (100 meters) will be constructed from precast concrete sandwich elements. Two systems with one goal: a perfectly airtight and water-resistant facade.

Complete custom sealing solution

Celdex developed a custom solution for both towers. "For the concrete facades, we apply our Seal4Prefab system," says Henny van der Heijden, Business Development Manager at Celdex. "Our Pre-Seal M foam tape provides high airtightness and thermal insulation. The EPDM Soft foam tape protects against driving rain." In addition, Celdex used Butyl tape 70S for horizontal compartmentalization to prevent moisture from penetrating between the precast elements. The timber frame elements were also fitted with Pre-Seal M foam tape on site. The balcony elements are fitted with EPDM cellular rubber strips for proper sealing and moisture protection. For the balconies of tower 1, where the suspension protrudes through the facade, Celdex developed a specific sealing solution.

Precast: faster and more efficient construction

Because the sealants were already applied to the concrete sandwich elements at the factory, the precast elements could be delivered and processed just-in-time at the construction site. "A new floor was delivered every eight days," Van der Heijden says. "Thanks to our preparation, the seals could be applied at lightning speed without slowing down construction."

Quality assurance to perfection

Celdex maintained strict quality control. "We advised on the best suited sealing products and organized a toolbox meeting," said Van der Heijden. "During construction, we randomly checked that everything was applied correctly. We carefully recorded this in quality assurance reports."