Tweha > Bonding Systems

Bonding systems

Bonding systems on behalf of rainscreen or ventilated cladding have been around for several decades now. Nonetheless it is still surprising to see how many people in the construction industry still question whether these adhesives can really hold those panels. Many stick to the old-fashioned mechanical connection solutions just because of the doubts they have about bonding. We could list well over a thousand projects that have successfully applied our bonding technology. Out of the rare incidents we have ever had, all were caused by an incorrect application. As long as that is done right, reliability is actually even better than mechanical connections.
Why is that you might wander? Actually this is only one of the many advantages that bonding systems have over mechanical connections. We love to share the most important ones with you and hope that after reading this, no doubts remain about the reliability and the many other advantages of bonded cladding technologies.


We all like a building that looks great. Architects are very creative and don’t like being limited by any construction limitations. This is probably the most important reason why bonding systems have entered this market many years ago. You won’t see any screws or other fixing materials sticking out. No matter what different types of materials you want to use, just put them next to each other using the same substructure and adhesive. It also doesn’t matter what form the panel has, bonding can stick anything to any background. In other words when you are looking for the greatest flexibility in design, bonded cladding is by far the best technology to use.

Greater choice of materials and lighter constructions

Bonding results in a better stress distribution in the façade panel due to the fact that the adhesive is applied over a larger area, enabling the use of thinner façade panels. Panel materials that due to their bending strength required a certain material thickness in case of  a mechanical connection (point load) and therefore could not be used, can now be thinner and used without any problems The use of thinner façade panels (less dead weight) also has the advantage that a lighter substructure can be used. Due to the lighter material, the application is significantly simplified.

Flexibility = durability

Thanks to the movement capacity of the TWEHA bonding products, durability is guaranteed.
Rainscreen or ventilated facades are subject to many different forces, be it wind, rain,
extreme temperatures and even earthquakes. The adhesive has the possibility to deform
along with the façade panel. By using screws for example you weaken the connected
material with one or more holes and the shrinkage and expansion of the panels cannot be
absorbed. The façade panel will buckle and in the worst case the panel will break off of the
façade. That will never happen with bonding systems.
Due to the permanent flexibility, it can absorb and endure severe impact, without tearing or
rupturing, giving it the capacity to withstand hurricane-force winds. TWEHA’s bonding
products provide a cushioned foundation to reduce the potential of damages making it an
exceptional choice for many structures within ‘earthquake zones’.

TWEHA’s Bonding Systems remain permanently flexible, without hardening, at extremely low
temperatures; an important consideration when bonding two materials together with different
coefficients of thermal expansion. While they provide a flexible foundation for movement,
even in freezing conditions, other bonding products can become brittle and crack, reducing
the safety factor of the structure. At the other end the TWEHA Bonding Systems are also
resistant to extremely high temperatures and do not break down with exposure to ultra-violet
rays. At elevated temperatures, the tensile strength, elongation and abrasion resistance of
these products is far superior to that of most organic rubbers. In fact after heat aging,
conventional rubber can harden, crack and decompose while TWEHA’s products remain
In other words the outstanding durability, flexibility and movement capacity are fundamental
to the high performance of TWEHA’s Products, making it an exceptional choice for
architects, builders and restoration firms.
Primers not needed!

Our competitors primers and TWEHA’s Cleaner+, Blacken, PreFix X-tra and Woodprotect are different products, though the impression they serve the same purpose. On the contrary, they have a different purpose, function and diverse constituents. First of all: with TWEHA’s Bonding Systems primers are no necessity! a. which greatly simplifies the application of our systems, one application-run less, thus reducing the risk for errors; b. you are not bound by a time limit in application as you are when using a primer; c. the lack of these dangerous primers reduces environmental and health risks, and d. the absence of a primer makes it possible to process the bonding system at low temperatures (< 5 °C). Actually, primers are aggressive problem solvers. Designed to penetrate to the substrate to ensure better adhesion. It increases covering capacity of the adhesive and thereby reduces the risk of failure and hides the shortcomings of the competitors adhesives in comparison with TWEHA’s Bonding Products. Primers generally consist of a reactive chemical agent which is dosed in a solvent. This solvent evaporates after application, leaving behind the active agent. This often aggressive agent ‘etches’ the surface to be bonded, so that the adhesive is able to penetrate. This leads to a change of the surface of the substrate. A crater-like structure is formed to accommodate the mechanical “cross-linking” of the adhesive. Different types of primers are required for different surfaces, depending upon their characteristics and acts as a “chemical bridge” between the substrate and the adhesive. Please note substrates and types of primer are not interchangeably! A most important disadvantage of using a primer is that the adhesive bead must be applied within a specified time after the application of the primer! So processing for both primer and bonding on the scaffold is an awkward and obstructive necessity. Finally aggressive primers are harmful to humans and environment.