Efficient and sustainable airtight construction

Industrialization of construction calls for new generation of precast sealing products

Celdex has been producing, advising and supplying plastic foam sealing products, which are excellent airtight, impact rainproof, waterproof, thermal and acoustic insulation, for 40 years. "We conceive, develop and produce all our products ourselves, at our own and modern equipped production site in Boxtel," says Jos ten Brincke, Sales Manager Airtight Building at Celdex. "As a result, clients benefit from short lines of communication and maximum flexibility. This allows us to respond very quickly to trends and market developments. Our solutions for prefab and airtight construction are a great example of this."

With the new generation of prefabricated sealing products, Celdex is responding to the rapid industrialization of construction, which is seen as an important solution to our housing shortage. "More and more contractor companies are turning into housing manufacturers, who are already prefabricating complete homes in their factories," Ten Brincke notes. "A logical development, because it is possible to build significantly faster and cheaper in the factories, without sacrificing quality and durability." Those who build in the factory are assured of the best working and climate conditions, he says. "In the factory it is always 18°C. It never rains or blows, ensuring the most ideal building conditions. Margins of error and failure costs are hardly an issue. Once finished, the homes are transported to the construction site in ready-made elements. From walls to floors, roofs and façade elements, which can be easily and quickly connected as 'puzzle pieces'." Assembly is increasingly becoming assembly, he emphasizes, which also allows savings to be made on technically skilled personnel. Thus, the classic carpenter on the construction site is no longer needed. "If our 'dry' sealing products are also pre-assembled in the prefab factory, sealing is also secured in one operation. This allows even more speed and enables contractors to meet requirements such as BENG, Zero-in-the-Meter and BREEAM-NL excellently."

Essential building blocks for an airtight home

Celdex saw the prefab building trend coming for some time and has been extensively surveying the needs and challenges in this area, says Ten Brincke. "Among other things, this led to our Dichtgarant and Seal4Prefab concepts, which provide construction stakeholders with all the essential building blocks to achieve and demonstrate the desired airtightness performance. Whereas fellow companies often still produce tapes, PUR foams and sealants, we specialize in 'dry' sealing products with foam tapes that can already be applied prefab in the factory. This makes the taping, masking or sealing of, for example, coupling seams on site a thing of the past."

Dense concept for ground-level housing

Within its extensive range of prefabricated sealing products, Celdex distinguishes between ground-level housing and high-rise projects. "With Dichtgarant, we offer a complete sealing concept for serial and industrial construction of ground-level housing," says Ten Brincke. "But also for all suppliers. For example, manufacturers of prefabricated hoods, chimneys, window frames and bathrooms. The concept includes the five steps of detailing, consulting, production, supervision and quality assurance and guarantees fast application, high comfort and a significant improvement in a building's energy performance, wind and water tightness and acoustic insulation." 

A revolutionary product within Dichtgarant is the EPDM Stelkozijnband, which guarantees durable air sealing of structural frames on limestone and concrete cavity walls. "The EPDM Stelkozijnband can be mounted on the stair frame directly from the reel after removing the release liner," Ten Brincke says. "The foam tape then obtains its sealing properties by compressing. To provide optimum protection against drafts, heat loss and noise, a compression from 20% is already sufficient."

Seal4Prefab sealing system for high-rise projects

To meet the challenges in high-rise projects as well, Celdex developed Seal4Prefab. This system includes both interior air sealing, insulating middle sealing and exterior driving rain sealing and is also suitable for prefabrication. "All our Seal4Prefab products are suitable for the simple and fast sealing of horizontal and vertical connection seams," said Ten Brincke. "The products are produced in long lengths and equipped with a high-quality self-stick, making prefabrication even easier. To ensure good and fast positioning of the elements and additional protection of the sealing tapes, all products are provided with a low-friction top layer." 

A nice development within Seal4Prefab is the Pre-Seal M foam tape, which has been specially developed for scaffold-free construction with both precast concrete sandwich and hsb elements. "Pre-Seal M combines minimal compression with extreme airtightness, within a wide joint range," said Ten Brincke. An important part of Seal4Prefab are knowledge transfer and quality assurance. "This starts with proper preparation and engineering. We provide advice on the best-fit sealing products and can test materials in advance in a critical building detail for wind and rain tightness. In addition, before assembly begins, a toolbox meeting is organized for the processors. During construction inspections on site, the processes are carefully recorded in partial reports, which together produce a single report for private quality assurance."