July 2022


ISO-Chemie’s multi-functional joint sealing tape ISO-BLOCO HYBRATEC was tested by Dr Feist of the Passivhaus Institute in Darmstadt for use in the construction of passive energy houses. Owing to its remarkable functional characteristics, ISO-BLOCO HYBRATEC was officially awarded the “Certified Passive House Component” label.

Key role played by window sealing in passive energy houses

This multi-functional tape, which was developed as a 3-level seal for window and door connections, was tested by the renowned institute to the strict specifications of the “Window connection air tightness system” test category. In passive house construction, it is very important for a building to be extremely air tight in order to minimise the heat input needed to heat the house. For window sealing, a high quality seal for the air tightness level plays an important role.


Tested under highly realistic conditions

To ensure performance in practice, ISO-BLOCO HYBRATEC was also tested under highly realistic installation conditions during the test procedure. This involved multiple tests with different window frame materials and in structural joints in both timber and solid constructions. The air tightness of the joint seal between window and wall was tested on both solid and lightweight construction walls. Timber walls made from air tight OSB board and phenolic resin-coated plywood were used for the timber construction method; these were bonded air tight with epoxy resin.



To test installation in solid walls, air tight lightweight concrete panels were used in conjunction with the IN FRONT OF WALL INSTALLATION SYSTEM ISO-TOP WINFRAMER „TYPE 3“. The IN FRONT OF WALL INSTALLATION SYSTEM used is also supplied by ISO-Chemie. ISO-TOP WINFRAMER „TYPE 3“ has already been recognised as a “Certified Passivhaus Component” by the Passivhaus Institute, which means that it is now approved for the installation of window elements in front of the wall in passive energy houses.


Air tightness saves on energy for heating

Having now achieved Passivhause certification, ISO-BLOCO HYBRATEC has proven its suitability as a “window connection air tightness system” for passive house construction.


This multi-functional joint sealing tape is equipped with a novel hybrid technology and offers outstanding results in all three sealing levels based on the 3-level model of the RAL “Installation guide”.


In the inner sealing level (the separation of room and external climate), the energy-efficient sealing tape was proven to have excellent air tightness and offers maximum thermal protection. Uncontrolled convection heat losses and draughts via the connection joint can be effectively eliminated – which is an important aspect in energy-saving construction.


Optimum moisture transport

By integrating multiple barrier layers in the form of foil firewalls, ISO-BLOCO HYBRATEC conforms to the RAL principle of “inside tighter than outside”. A high drying effect allows moisture from the joint to be dissipated outside in a controlled manner, thus drying it out. This avoids mould formation and the possible resulting structural damage right from the start.


Passivhaus-certified 3-layer multi-functional tape with hybrid technology

Resistant to driving rain to more than 1050 Pa

In the functional area, ISO-BLOCO HYBRATEC has high acoustic and thermal insulation values. The MF-1 certified multi-functional tape also impresses in the weather protection level, offering over 1050 Pa resistance to driving rain. In view of the climate change issues and increasingly frequent extremes of weather with violent storms and heavy rainfall, good protection against driving rain is of immense importance for investors, owners and residents alike.


ISO-BLOCO HYBRATEC also combines considerable expansion force with excellent functional reliability in terms of capacity to absorb movements in the long term. ISO-Chemie offers a 10-year functional warranty on the product.


RAL quality mark & EC1PLUS seal

ISO-BLOCO HYBRATEC has already won multiple awards. The sealing product was awarded the RAL “Joint sealing components and systems” quality mark from the RAL Gütegemeinschaft Gebäudeabdichtungssysteme e.V. It also carries the EC1PLUS seal and, as a “very low-emission” product, belongs to the EMICODE® Premium Class based on the criteria set out by the Gemeinschaft Emissionskontrollierte Verlegewerkstoffe, Klebstoffe und Bauprodukte e.V. (GEV – Association for the Control of Emissions in Products for Flooring Installation, Adhesives and Building Materials e.V.) - another distinction for environmentally-friendly construction. And, of course, the multi-functional tape also meets the requirements of the German Building Energy Act (GEG).


Contribution to the energy revolution

Passivhaus-certified products offer planners, construction companies and building owners a high level of certainty for the successful construction of a passive energy house. Several other of the manufacturer’s energy-efficient and sustainable building sealing products have already been certified as suitable components for passive house construction. In addition to the multi-functional joint sealing tapes ISO-BLOCO HYBRATEC and ISO-BLOCO ONE, the in front of wall installation systems ISO-TOP WINFRAMER „TYPE 1” and „TYPE 3” have also been certified by the Passivhaus Institute. The ISO-Chemie products help to reduce the primary energy consumption of buildings, thus contributing to the success of the energy revolution.


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