Home > Companies > Siderise Group > SIDERISE Fire and Acoustic Closer for Party walls (formerly Lamatherm FAC)

Fire and acoustic party wall closer comprising a strip of semi-rigid mineral wool insulation bonded to a black polyethylene dpc. It reduces flanking sound transmission at the junction of compartment and external walls and can be readily cut as required. Meets requirements of Building Regulations (E&W) Approved Document E (2003 edition).

  • Economical and easy to install.
  • Provides a smoke and fire seal.
  • Provides up to 120 minutes fire integrity and insulation.
  • Qualified acoustic performance.
  • Quality assured to BS EN ISO 9001.
  • Suitable for both horizontal and vertical applications.
  • Suitable for use in cavities in typical external wall applications.
  • Tested utilizing the principles of BS 476-20 and BS EN 1366-4.

Standard product features

Insulation size:

1200 x 260 mm.


  • Length: 1300 mm.
  • Side laps: 40 mm.
  • Bottom lap: 100 mm.

Thermal conductivity:

0.035 W/mK.



Other thicknesses to suit different cavity widths are available upon request; contact manufacturer for more information.

NBS Specification

NBS Create logo
This product is associated with the following NBS Create clause:
45-25-20/455 Plastics cavity closers

Product specification

An important note about specifying



Siderise Group


+44 (0)1656 730833

Product reference


Insulation thickness

[50 mm]
[65 mm]
[75 mm]
[100 mm]

Manufacturer details

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