Once the decision is made to apply the terrazzo floor, there is still a choice between two basic options –
mineral terrazzo and resin terrazzo floor. It is worth knowing how these systems differ to choose the best solution for a specific investment project.
Traditional mineral terrazzo is a floor made of rock aggregate embedded in a cement binder, repeatedly ground and polished until a smooth surface is obtained. It has a decorative finish in the form of a subtle pattern created by a fine aggregate dispersed in a mineral mass.
Nowadays, new technologies based on synthetic resins have revolutionized the way of designing and application of terrazzo floors. Seamless resin systems are so versatile that architects can treat floors in large commercial projects like canvas on which they create works of art. The use of mass based on epoxy or polyurethane resins and marble aggregate allows one to create almost any pattern on the floor. The fields in different colours are separated by aluminium strips. After filling all the fields and curing of the floor, it is repeatedly ground, then coated with lacquer and polished to obtain a smooth, shiny finish.
Epoxy resin terrazzo
The basic advantages of using resin terrazzo include greater design freedom in terms of colours and shorter application time. The use of epoxy resin as a binder allows to obtain a thin system (with thickness of 7–8 mm) with a smooth, elegant finish, which consists of a coloured background and marble or granite aggregate. The resin binder colour palette is unlimited. This type of flooring is made directly on a concrete surface, and at the same time it is lightweight. Due to the low shrinkage of the binder, the resin terrazzo does not need to be dilated, it should only have cuts that reflect the anti-shrinkage dilatation of the concrete substrate.
Resin terrazzo allows for the creation of multi-coloured, even the most sophisticated patterns on the floor surfaces inside buildings. With appropriate conditions, the grinding process of the resin terrazzo can be started after 48 hours, which allows for a shorter application time than with the mineral terrazzo. In moderate climates, this floor is not suitable for outdoor use due to its smooth surface, which has too little slip resistance during rainfall.
Mineral (cementitious) terrazzo
Selected mineral terrazzo floors are suitable for use even in very demanding conditions, including outside buildings or in old buildings, if there is no moisture insulation under the concrete substrate.
Mineral terrazzo is made of a mass consisting of a cement-based binder and aggregate. In this way, it is customary to define a whole group of different floor systems. They are thicker and heavier than resin floors. However, it should be remembered that terrazzo based on cementitious binder may shrink, which causes irregular cracking of the floor. Therefore, the floor layer should be divided into fields with expansion joints.
With this system, polishing can be started only after the floor binding process is complete, which lasts up to 7 days. During this time, the application zone is excluded from normal use. For many entrepreneurs, this can cause serious difficulties and financial losses associated with the closure of the facility or part of it.
Although mineral terrazzo floors are not available in such a wide range of colours as resin terrazzo systems, this solution allows obtaining many attractive, natural earth tones.
Considering the use conditions, one should remember that resin terrazzo is water impermeable and stain resistant, whereas the cement-based mineral terrazzo floor poses the risk of liquid absorption and permanent stains.
The main differences between the two types of terrazzo floors are shown in the table below.
Flowcrete Polska supplies both materials and technologies for the application of resin terrazzo floors, as well as impregnation and concrete protection agents used for the application of mineral terrazzo floors. The selection of the appropriate system depends on the conditions and assumed loads as well as the expected visual effects.