Home > Companies > Siderise Group > SIDERISE CBX Flexible Acoustic Barriers for Suspended Ceilings (formerly Lamaphon CBX)

Flexible composite quilts designed for free-hanging in ceiling voids above partition lines. They have been specifically developed to provide a simple solution to the common problem of improving `room-to-room' sound separation via a common ceiling void. All grades offer exceptional sound reduction properties in comparison to common ad-hoc solutions using standard flexible/ resilient materials.

SIDERISE CBX acoustic ceiling void barriers are multi-layered composite materials. The central layer is a thin flexible heavy septum membrane. Two types of membrane are available; lead foil or a polymeric heavy salt loaded barrier. Both types incorporate to one side a laminated glass fabric 'anti-creep' layer. This is designed to prevent possible long-term elongation of the product in its normal free hanging condition. Additionally, this layer provides additional reinforcement to through penetrations at fixing points. Both types of central membranes provide matching acoustic performance for each of the two standard surface weight options. The primary difference between the types is their mechanical characteristics when bent or deformed. The lead foil membrane has a tendency to memorize deformation. Each side of the membrane has a soft high-tensile glass fibre insulation layer, faced on the exposed surface with a reinforced aluminium foil. It is extremely quick and easy to install and is suitable for both new build and refurbishment projects.

Standard product features


Bright reinforced aluminium foil to both surfaces.

Thickness (nominal):

40 mm.


  • CB5 and CB10: 1800 x 1200 mm; special lengths are available, contact manufacturer for more information.
  • CB5P and CB10P: 2000 x 1200 mm.

Thermal conductivity:

0.035 W/mK.

Sound reduction:

  • CB5 and CB5P: 29 dB (Rw).
  • CB10 and CB10P: 33 dB (Rw).

NBS Specification

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This product is associated with the following NBS Create clause:
45-45-70/445 Coated woven glass fibre cloth flexible cavity barriers

NBS Specification

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This product is associated with the following NBS clauses:

Product specification

An important note about specifying



Siderise Group


+44 (0)1656 730833

Product reference

Lead foil central membrane, 5 kg/m².
Polymeric barrier central membrane, 5 kg/m².
[CBX CB10]
Lead foil central membrane, 10 kg/m².
Polymeric barrier central membrane, 10 kg/m².

Manufacturer details

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