CLASSIFICATION OF ADHESIVES
All tile adhesives have a combination of letters and numbers directly in the name or under the name.
Learn how to understand what each letter means. The right choice is important. The label alone will often tell you which adhesive is right for your project.
Differentiation based on binder
All tile adhesives have a combination of letters and numbers directly in the name or under the name. The first letter indicates the type of binder.
- C - Cementitious tile adhesives are frost and water resistant, making them suitable for outdoor use. Cementitious adhesives are the standard for tile installation and are suitable for all solid and absorbent substrates such as levelling compound, concrete, lime and cement plaster.
- D - Dispersion adhesives are ready-to-use in a bucket and do not need to be mixed with water. They are suitable for interior use only and are not frost resistant. These adhesives have a high adhesive strength and are therefore suitable for smooth substrates. Dispersion adhesives dry relatively slowly but remain flexible once cured. They are also used when replacing damaged tiles.
- R - Reactive resin adhesives meet very specific requirements, especially in applications such as commercial kitchens. Reactive resin adhesives also adhere well to unusual substrates such as glass or metal, due to their very high adhesive strength. Epoxy or polyurethane based resin adhesives must be mixed with a hardener before use. Once cured, they are flexible and resistant to chemicals.
Differentiation on the basis of adhesion
- C1 - This type of adhesive has a lower adhesive strength of at least 0.5 N per square millimetre (Newton per square millimetre). This is a basic adhesion strength that is suitable for interiors with low mechanical loads. For example, they can be used in toilets and other places that are not exposed to moisture.
- C2 - These adhesives provide a higher bond strength of more than 1 N per square millimeter (Newton per square millimeter). They are ideal for bathrooms and for floors with underfloor heating.
Classes F, T, E
- F - the letter F stands for "fast" and in practice it means the speed of hardening. Fast drying adhesives, as the name suggests, allow for fast construction and early use of the covering. This is important, for example, for stairs. On the other hand, they need to be processed very quickly.
- T - stands for "thixotropic" and refers to the increased stability of the adhesive. This reduces slipping of the tiles during gluing. This adhesive is often used for heavy wall tiles.
- E - stands for "extended" and refers to the extended open time of the tile adhesive. As a result, these adhesives are used for work and finishing even on large areas.
Of course, a combination of letters is also possible in the designation of adhesives, where tile adhesives have several of these properties, for example FT or TE.
S1 or S2?
Tile adhesives must have a certain flexibility to withstand stresses caused by thermal expansion, for example. Otherwise, the tiles could crack or come off the substrate. This elasticity is measured by means of a so-called bending test. Only adhesives with a value of S1 or S2 are classified as flexible. Adhesives are classified into two classes according to the measured value of the transverse deformation:
- S1 tile adhesives: these are deformable adhesives with a transverse deformation ≥ 2.5 mm. This is the elasticity before they crack. They are suitable for example for outdoor sunlit areas.
- S2 tile adhesives: are highly deformable adhesives with a transverse deformation ≥ 5 mm. Which in practice means that they can be bent at least 5 mm before they crack. They are very flexible and can be used for very special applications.
