Sound insulation is a key factor in improving quality of life and acoustic comfort in residential buildings, commercial spaces, and entertainment venues.

Sound insulation is the process of limiting the transmission of sound from one space to another. Its purpose is to reduce noise disturbance, whether originating from external sources or from within a building.

Sound is transmitted in two main ways:

• Airborne sound
  This originates from sources such as speech and music and is transmitted through the air.
• Impact sound (vibrations)
  This is caused by physical vibration, such as footsteps, moving furniture, or machinery, and is transmitted through building elements (floors, walls, ceilings).

The basic principles of sound insulation

• The greater the mass of a material, the more difficult it is for sound waves to pass through it. For example, a thick concrete or brick wall provides much better sound insulation than a gypsum board panel.
• Certain materials have the ability to absorb part of the sound energy, thereby reducing noise and sound reflection (reverberation).
• Layer separation is required in order to structurally isolate building elements and prevent direct contact and vibration transmission.
• Even small gaps or cracks can allow sound to pass through. Proper sealing of joints, frames, and cracks using special soundproofing gaskets or silicones is essential.

The selection of suitable materials depends on the type of sound to be addressed (airborne or impact), as well as on the construction element (wall, floor, ceiling).

Floating Floors
Anti-vibration underlays are used to separate the structural slab from the cement screed, in order to reduce impact noise such as footsteps or furniture movement. Polyethylene and rubber exhibit elastic behavior, absorbing vibrations before they are transmitted to the building structure. At the same time, they provide thermal insulation and moisture protection, especially in the case of closed-cell materials such as Isolfon Rerub and Isolfon FF. Typical applications include installation under parquet, laminate, or tiled floors, as well as underlays in floating cement screeds.

Acoustic Improvement – Sound Absorption
For sound absorption and improvement of a room’s acoustic behavior, polyurethane foam panels such as Isolfon Sep and Isolfon SE.PY are commonly used. They are ideal for studios, theatres, cinemas, and music halls. Polyurethane sound-absorbing panels trap sound waves and reduce reverberation and unwanted sound reflections. Although they do not provide significant sound insulation (i.e. they do not block sound transmission to other spaces), they significantly improve the acoustic quality of the room. They are available in various forms—pyramidal, wave-shaped, or flat—depending on the requirements of the acoustic study.

Sound absorption in walls and suspended ceilings
Fibrous materials, such as mineral wool, glass wool, and polypropylene fibre boards (Aritherm), are key components in dry construction systems and double-wall assemblies. These materials offer excellent sound-absorbing properties while also providing thermal insulation. They are typically installed between gypsum boards or within wall and suspended ceiling cavities, contributing significantly to noise reduction.

Sound insulation in walls and suspended ceilings
The viscoelastic membrane Isolfon Barrier is a flexible, high-mass material used to increase mass and improve sound insulation in walls, floors, and ceilings. This membrane reflects and absorbs part of the sound energy, operating with particularly high efficiency. It is typically installed between two layers of gypsum board and in combination with mineral wool, creating high-performance composite sound insulation systems.

Elements such as polyethylene or rubber strips used under machinery bases, suspended ceiling hangers, and vibration-damping supports for gypsum boards are considered critical points for the proper performance of sound insulation systems.