Frequently asked questions
TWEHA’s adhesive systems are unique. Besides their strength and durability, the major difference between them and other solutions is the absence of a hazardous primer:
– this simplifies the processing of our systems, as there is one less application run, which also significantly reduces the risk of errors;
– you are not bound by a time limit in processing as prescribed when using a primer
– the absence of these hazardous primers reduces environmental and health risks, and
– the absence of a primer makes it possible to process the adhesive system at low temperatures.
The correct dimension of a adhesive bead is 8mm in width and 8mm in depth in a triangle shape to avoid air bubbles when pressing together.
In general, these products should be stored between the range of 5°C to 25°C (41°F to 77°F)
It is also important that moisture does not get into the packaging as it will start the curing process and the product will become hard and unusable. The shelf life of our adhesives is 18 months.
Framework must consist of preserved, dried back pinewood with a maximum wood moisture percentage of 18%. The wood moisture percentage can be measured by means of a wood moisture meter with the pins.
The center distances of the framework are specified by the panel manufacturer and can often be found in their Technical Data Sheet. In common the maximum distance is 600 mm (24 inch).
When bonding panels, we use a minimum temperature of -20°C (-4°F) and a maximum temperature of 40°C (104°F) and the relative humidity also plays an important role in this. A dew point calculator app is available for this. There should be no rain/precipitation.
No, the surface to be bonded must be dry, clean and free of moisture. Clean with TWEHA Cleaner+ and start to bond!
Only in case of fiber cement board you need to apply TWEHA PreFix X-tra, a surface improver to avoid moisture transport behind the adhesive bead.
For more information, please have a look at our Knowledge Box.
There must always be a continuous air cavity at the back of the panels of at least 20 mm and ventilation openings at the bottom and top of the panel system of at least 50 cm²/m¹ or 100 cm²/m¹ depending on the type of panel. In addition, the TWEHA panel bonding system is 3 mm thick ultimately and a drain would be formed on horizontal details were water load can be collected and finally damage the structure, cause water and dirt transport through the panel which in time become visible.
For more information, please have a look at our Knowledge Box.
The open time of the TWEHA adhesives 10 minutes.
That is depending on the weight and dimensions of the panel to be bonded. The adhesive suction and the double-sided self-adhesive foam tape provides the 1st adhesion and gives the adhesive time to reach its final strength. Mechanical support is most of the time not necessary.
Panels may be bonded as facade and ceiling panels, keep in mind that the framework are mounted perpendicular to the facade and that the center-to-center distance of the framework is always x 0.70 in relation to the center-to-center distance in the facade.
Fire resistance is based on a construction’s influence on the start of and contribution to a fire.
The European classification according to EN 13501-1 distinguishes seven main classifications (A1, A2, B, C, D, E and F), with the following two additions:
• “Class s” for smoke development (s1, s2, and s3, where s1 is the highest sub-classification).
• “Class d” for the formation of burning drops and particles (d0, d1, and d2, where d0 is the highest sub-classification).
Every component of a construction determines the result, such as the panels, the support construction, the installation method, and any insulation material used. With regards to the support structure construction, aluminum is nonflammable with a melting point of about 1,202°F (650°C). The most determining factor, however, is the panel itself. Mineral wool and porcelain tile tends to be the preferred material with a class A1 or A2 rating.
TWEHA has conducted various fire tests showing that, regarding fire safety (fire classification according to EN 13501-1), legal requirements can be met. Fire resistance is the ability of a building system to meet the requirements relating to fire stability, flame resistance, and thermal insulation for a certain period of time. The cladding/ façade panel determines the overall performance of the TWEHA bonding systems with regard to fire resistance.
For more information, please have a look at our Knowledge Box.