Sound insulation with cavity filling

Why does cavity wall insulation provide soundproofing?

An cavity already provides a certain degree of sound insulation by itself. This is not due to the air in the space, but because of the distance between the two walls. Sound waves lose energy as they travel further, but air itself is a good conductor of sound. By filling the cavity with insulating material, sound waves are impeded. Thus, the sound diminishes not only through distance but also through the resistance of the material in the cavity.

What material is suitable as cavity filling?

When choosing a suitable cavity wall insulation material for soundproofing, it is important that the material has insulating properties. Examples include Cyclin, EASYpol and Ecosorb Metisse.

• Cyclin is the most environmentally friendly choice. This bio-based material is 100% circular and has a high mass, which ensures excellent sound insulation performance. Thanks to its higher specific weight, the material effectively contributes to reducing sound transmission.
• Ecosorb Metisse is made from recycled jeans and is therefore a 100% circular solution.
• EASYpol is largely made from recycled synthetic fibres from PET bottles.
• EASYpol and Ecosorb Metisse are more cost-effective, but still provide effective noise reduction. Moreover, these materials are easy, comfortable, and clean to process, as no dust or unpleasant fibres are released.

In which constructions is cavity filling effective?

Cavity filling can be applied in all constructions where a cavity is present, such as in internal walls, floors, and roofs. It is therefore a versatile solution for both thermal and acoustic insulation. An important rule of thumb is that at least 70% of the cavity must be filled with cavity filling, preferably evenly distributed across the entire surface.

Cavity filling in self-built structures

Cavity filling is used in both renovation projects and in self-built solutions, such as a partition wall, floating floor or floating ceiling. By combining cavity filling with a decoupled construction, both airborne noise and impact noise are effectively insulated.