Home > Companies > Siderise Group > SIDERISE CVB Acoustic Void Barriers (formerly Lamaphon CVB)

SIDERISE acoustic void barriers are primarily intended to reduce sound transmission via hidden voids offering potential 'cross-talk' paths to adjoining areas. Typical examples include suspended ceiling or raised access floor voids at partition lines and the cavity formed at floor slab abutments to curtain walls.

As standard, the product incorporates opposing interlocking rebate joints in one direction. This feature helps maintain acoustic integrity at joints within the installed barrier. SIDERISE acoustic void barrier - facades is available in a number of grades and thicknesses offering a wide range of sound reduction values. The product is also available with a choice of optional high mass central membranes to achieve substantially higher SRI values. Some acoustic void barriers - facades have certified fire resistance permitting their dual use as ceiling or floor void fire barriers. The product is extremely simple to fix and can be easily cut to accommodate service penetrations.

The rockfibre insulation core is available in two different structural forms:

  • SFO (conventional, i.e. direction of the internal fibres predominantly aligns with that of the barrier itself).
  • HSL (special ‘lamella’ construction, i.e. the internal fibres have a perpendicular orientation and additionally are held in a pre-compressed state).

The SFO form is also optionally available with the inclusion of a central limp heavy membrane. Two surface weights of the polymeric membrane are available: P5 (5 kg/m²) or P10 (10 kg/m²).

Standard product features


High-density resin bonded rock fibre insulation core with exposed faces finished in a Class ‘O’ reinforced aluminium foil.


1200 x 1200 mm, 1200 x 1000 mm or 1200 x 900 mm according to grade, contact manufacturer for more information.

Fire performance (to BS 746-7):

Class 1.

NBS Specification

NBS Create logo
This product is associated with the following NBS Create clause:
45-45-70/450 Wired mineral wool batt flexible cavity barriers

Product specification

An important note about specifying



Siderise Group


+44 (0)1656 730833

Product reference

HSL, 90 mm thick, 7.1 kg/m², 23 Rw (dB).
HSL, 120 mm thick, 9.4 kg/m², 25 Rw (dB).
SFO, 100 mm thick, 10 kg/m², 19 Rw (dB).
SFO, 100 mm thick, 14 kg/m², 21 Rw (dB).
SFO + P5, 103 mm thick, 13 kg/m², 28 Rw (dB).
SFO + P10, 105 mm thick, 18 kg/m², 31 Rw (dB).
SFO + P10, 55 mm thick, 14 kg/m², 52 Rw (dB).

Manufacturer details

Forge Industrial Estate,
Mid Glamorgan, CF34 0AY
Tel +44 (0)1656 730833
Fax +44 (0)1656 812509
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