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

Flexible composite sheets designed for free hanging in ceiling voids above partition lines. They provide a simple solution to the common problem of improving `room to room' sound separation via a common ceiling void. The barrier’s flexibility allows it to be easily deformed around localized obstructions within the ceiling void.

SIDERISE flexible acoustic barriers for suspended ceilings 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. On each side of the membrane is a Class ‘O’ open cell acoustic foam insulation layer. 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. It is extremely quick and easy to install and is suitable for both new build and refurbishment projects.

Standard product features

Thickness (nominal):

13 mm.


2000 x 1200 mm.

Sound reduction:

  • FL5 and FL5P: 23 dB (Rw).
  • FL10 and FL10P: 27 dB (Rw).

Fire performance (to BS 746-7):

Class 1.

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.
[FLX FL10]
Lead foil central membrane, 10 kg/m².
Polymeric barrier central membrane, 10 kg/m².


[Bright reinforced aluminium foil on one side]
[Matt black open cell foam both sides]
Manufacturer's standard.

Internal glass fabric anti-creep layer

[Not required]
If aluminium foil finish is selected.
Minimizes the risk of possible long-term elongation in high void conditions.

Manufacturer details

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