The durability of geotextiles under average conditions is very high, sufficient for road construction needs. The importance of the durability factor depends on the type of application. It is less relevant for short-term applications, such as:

• separation layers under the laid embankment soil, treated as process support, needed mainly at the time of construction,
• reinforcement of embankments on weak subsoil, the load-bearing capacity of which increases over time due to soil consolidation to such an extent that it can take the load itself.

Durability is essential for long-term applications in relation to:

• strength and deformability – the reinforcement of soil masses (retaining structures, steep slopes, embankments on piles), the safety of which should be ensured by the strength of the geotextiles, as well as the reinforcement of the pavement subgrade,
• the water permeability of filters in drainage systems.

Durability is determined by resistance to climatic (atmospheric) factors and chemical and biological influences. In general, products should be protected from prolonged exposure to light. The products are usually UV-stabilised with additives, e.g. carbon black, so that they can withstand even prolonged exposure. However, it is recommended that the geotextiles are quickly embedded and covered with soil. If the geotextiles are not covered with soil on the day of installation, they should be tested for accelerated weathering according to EN 12224. Resistance to climatic factors is determined by testing the strength of the material in a special apparatus, exposing it to UV light at a standardised irradiation energy, with periodic sprinkling.