Do rubber tiles and rubber mats change dimensions with heat, moisture and ageing?

Rubber tiles and rubber mats can undergo slight dimensional changes with heat, moisture and ageing. Temperature has the greatest short-term effect: tiles expand when warmed and contract again as they cool. This temperature-related dimensional change is largely reversible.

In porous tiles, moisture initially increases weight, and water may remain within the pore structure. The rubber compound and binder can absorb small amounts of water, which may cause a slight temporary dimensional change. On drying, this moisture-related change largely reverses.

Over time, ageing of the material structure can lead to slight permanent shrinkage. For comparable product construction, ageing shrinkage is lower with EPDM granulate than with ELT granulate from end-of-life tyres.

The extent of dimensional change depends on the material composition, compaction, binder, tile geometry and ambient conditions. On installed surfaces, slight dimensional changes can accumulate across several tiles and become visible at edges or joints.

Before installation, all tiles should be at approximately the same temperature and should not have been heated by direct sunlight. The dimensional tolerances stated in the product data sheet apply to the measurement conditions specified there; they do not represent an upper limit for thermal expansion.