Acoustic Sealing or Sound Insulation in buildings is of great significance to the health and well-being of the occupants. Sound insulation is of particular importance in residential construction because an apartment provides not only a place of rest and relaxation, it also serves to screen off the personal domestic environment from that of neighbours. Specific regulations apply to certain types of buildings such as schools, hospitals, hotels and office accommodation.

The sound insulation requirements to be complied with are laid down in directives, standards and regulations throughout the world. FML use firestop products which are not only tested and approved internationally in accordance with the stipulations of passive fire prevention regulations, they are also comprehensively tested to ensure compliance with sound insulation requirements.

  • Airborne Sound
  • Structure Borne Sound
  • Airborne Sound Insulation
  • Structure Borne Sound Insulation

Airborne Sound

Airborne sound is the term applied to fluctuations in pressure which spread out in a wave pattern and thereby induce oscillation in the objects or parts of a structure they collide with.

Airborne sound in buildings is transformed into structure-borne sound as it strikes walls, floors or ceilings and is passed on through the structure in this form before subsequently radiating into neighbouring rooms as airborne sound. At the same time, the sound becomes weaker as it passes through a wall or ceiling.

Structure Borne Sound

Sound that carries or spreads through a solid object is known as structure borne sound. Structure borne sound is usually not perceived as sound or noise but is noticed, if at all, in the form of vibration. It becomes audible, nevertheless, when radiated from the surfaces of the structure and thus transformed into airborne sound.

As the energy loss in the transmission of structure borne sound through solid objects is minimal, the sound can travel over great distances. Accordingly, measures must be taken to isolate living accommodation and other occupied rooms from structure borne sound.

Airborne Sound Insulation

Airborne sound insulation is understood to mean the measures taken to reduce the transmission of sound between two adjoining rooms. The reduction in sound transmission depends, above all, on the mass of the structural component separating the rooms.

Structure Borne Sound Insulation

In contrast to airborne sound, structure borne sound is transmitted through solid objects. It subsequently becomes audible, however, when radiated from surfaces and transformed into airborne sound. Structure borne sound spreads through solid objects with little loss and thus makes sound reduction measures necessary. Structure borne sound is generally understood to mean sound generated and transmitted into the structure of a building by installations such as toilet flushing systems. Footstep sound, however, is also regarded as structure borne sound. The transmission of structure borne sound in buildings is controlled by various national regulations (DIN, Approved Document E).

The transmission of structure-borne sound from plumbing installations into walls or ceilings can be reduced by FML through the use of acoustically-insulated pipe rings. In floors, the transmission of footstep or impact noise can be reduced through application of a floating screed layer with the appropriate acoustic insulation characteristics.

Measures must also be taken to prevent the transmission of oscillations or vibration to the structure where pipes or cable trays pass through walls or ceilings. Sound will otherwise be radiated as airborne sound from the walls or ceilings. In accordance with Approved Document E, pipes must be isolated from the structure by a suitable, acoustic insulation material and the gap between the pipe and the wall or floor filled with a suitable sealing compound. In contrast to airborne sound, the procedure for testing for structure-borne sound transmission is not standardized.

Approved Document E