Askeläänieristysindeksi

Askeläänieristysindeksi, often abbreviated as IIC (Impact Insulation Class) in English, is a measure used to quantify the sound insulation performance of floor constructions against impact sound. Impact sound is generated by footfalls, dropped objects, and other activities that create vibrations transmitted through the floor. The higher the Askeläänieristysindeksi value, the better the floor construction is at reducing the transmission of impact sound to the space below.

The index is determined through standardized laboratory testing. A tapping machine, designed to simulate various impact sounds, is placed on the floor surface. Sound pressure levels are then measured in the receiving room directly below the tested floor. The Askeläänieristysindeksi is calculated based on these measurements, typically using a specific weighting curve that aligns with human perception of impact noise. Different octave bands of sound are considered, and the final index is a single-number rating that represents the overall performance.

Common floor constructions, such as concrete slabs, timber joist floors, and floating floors, will have different Askeläänieristysindeksi values. Factors influencing this index include the mass of the floor, the presence of resilient layers (like acoustic underlays or mineral wool), and the rigidity of the construction. In building regulations and acoustic design, minimum Askeläänieristysindeksi requirements are often specified to ensure adequate sound insulation between dwelling units or between different building zones. This helps to create more comfortable and peaceful living and working environments by minimizing noise disturbance from foot traffic and other impact sources.