The European standards community created a classification system to help simplify the selection of tile installation materials which include adhesives, grouts, membranes and screed. The goal of the EuroNorm (EN) standards is to establish a product classification code for the European community to quickly and easily tell an architect, specifier, tile contractor or distributor and exactly how a product is designed to perform.
The standard demands for a proper performance test before it is provided with a Performance Certificate. This certificate consists of letters and numbers that are easy to understand. EN classification system is more encompassing than the ISO classification system.
The types of tile adhesives according to the EN 12004 are:
A. Types of Adhesives
· Cementitious Adhesives C
· Dispersion Adhesives D
· Reaction Resin Adhesives R
B. Classes of Adhesives
· Normal Adhesives 1
· Improved Adhesives 2
· Fast – setting Adhesives F
· Adhesive with Reduced Slip T
· Adhesive with Extended Open Time E
· Deformable Adhesives S1
· Highly Deformable Adhesives S2
The different symbols and categories have their own meaning which are defined below:
Cementitious Adhesive– The C adhesive is a mixture of hydraulic binding agents such as portlland cement, aggregate and organic additives like moisture retention additive, latex polymers etc.) to be mixed with latex admix or water before mixing.
Dispersion Adhesive – The D type adhesive is a type of ready to use mixture composed of organic binding agents in the form of an aqueous polymer dispersion, organic additives and mineral fillers which are the mastic type products.
Reaction Resin Adhesive– This R type adhesive is a single or multi-component mixture of synthetic resin, mineral fillers and organic additives in which curing occurs by chemical reaction like epoxy or urethane based products.
Class 1 – Also called as 1 type, these adhesives have passed the minimum pass level tests that are mandatory for that adhesive type.
Class 2 – Also called as 2 type, these adhesives have passed the same test as Class 1 and other higher pass levels too.
Extended Open Time – It is the maximum time interval after the application at which tiles can be put in the applied adhesive and meet the tensile adhesion strength requirement which is always more than 30 minutes after the application of the adhesive. This designation is not applied to Reaction Resin Adhesive ( R ).
Slip – Resistance ( T ) – The downward movement of tile applied to a combed adhesive layer on a vertical surface must be ≤ 0.5mm for a C or D type adhesive and ≤ 5mm for a R type adhesive.
Fast – Setting ( F ) – They are adhesives that must achieve the minimum strength requirements of fast setting adhesives with accelerated cure time.
Deformability ( S ) – It is the capacity of hardened adhesive to be deformed by stresses applied between the tile and the substrate without any damage to the installed surface.
To pass S1 requirements an adhesive must be able to deform ≥ 2.5mm but < 5mm. To pass S2 requirements an adhesive must be able to deform ≥ 5mm.