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Siderise RF – Cavity Barriers and Fire Stops for Raised Access Floors – Technical Data

Version: 1.11 - Release Date: February 2022


Siderise RF Systems prevent the spread of fire and smoke, and reduce sound transmission, by sealing the voids between raised access floors and floor slabs.

The range includes options to either subdivide large uninterrupted cavities (Cavity Barriers) or to provide continuity of fire resistance when aligned underneath partitions (Fire Stops). Across the range, these simple to install systems have been tested for fire performance, acoustic performance and for use as a plenum liner. 

Siderise RF-CB cavity barrier systems are used to subdivide uninterrupted voids in accordance with Building Regulations and offer 30 minutes fire resistance (EI 30). CB barriers are designed to suit individual floor void depths between 50mm and 600mm (see Table 1 for ratings by void size) 

Siderise RF-FS fire stop systems  maintain continuity of fire resistance for installations aligned with fire rated partitions hence maintaining compartmentation. The 'FS' systems offer 60 to 120 minutes fire resistance. 

RF-FS barriers are designed to suit individual floor void depths between 50mm and 600mm. They have been designed as a one-piece system and afford easy cutting and installation. Additionally, due to a unique manufacturing process, the products also offer unique vertical compression to allow tightness of fit.

Siderise RF Systems have Certifire 3rd party approval (CF 5646) please refer to Table 1 for details.

Product Description

Siderise RF cavity barrier and fire stop systems are classified A1 to EN 13501-1 and comprise a unique non-combustible stone wool lamella core, which is faced on two sides with an impervious aluminium foil, offering excellent resistance to the passage of smoke.

Siderise RF is available in the following forms:

Pre-cut Strips
• Pre-cut products are available in 1mm increments of width to suit the cavity size. Please see Table 1 regarding 'fit type'.
• Supplied with appropriate brackets as part of a system.

• Standard sheet size is 1200 x 1200mm and may be of benefit when the actual void size is not known or where it varies significantly.
• Appropriate brackets must be ordered separately.

Fire Performance

Siderise RF cavity barrier and fire stop systems have been successfully tested to the latest European standards - EN 1366-4 for up to 120 minutes fire resistance (integrity and insulation). 

  • Some options have additionally been 3rd party certified under Certifire CF 5646, please see Table 1 for details.
  • In terms of 'Reaction to Fire', the products are classified  'A1' to EN 13501-1.

Table 1 : Resistance to Fire to EN 1366-4

Void Height Product Ref. Product Compression Bracket Requirement Classification 3rd Party Certification 
(mm)   Thickness (minimum) Range (mm) (EN 13501-2) (Product Ref) 
50 to 200 RF-CB30 75mm +10mm 2no. B195 EI 30 
 RF-FS60 90mm +5mm No brackets EI 60 Certifire CF 5646 (RF 60/60) 
 RF-FS120 120mm +10mm 2no. B195 EI 120 
201 to 300 RF-CB30 75mm +10mm 2 no. B195 EI 30 
 RF-FS60 90mm +10mm 2 no. B195 EI 60 
 RF-FS120 120mm +10mm 2 no. B195 EI 120 
301 to 400 RF-CB30-X 90mm +10mm 2 no. B355 EI 30 Certifire CF 5646 (RF 60/30) 
 RF-FS60-X 120mm +10mm 2 no. B355 EI 60 
401 to 600 RF-FS60-X 120mm +20mm 2 no. B355 EI 60 
  • Brackets must be installed at 600mm centres based on a 1200mm strip. This can be reduced pro rata for shorter lengths. Please note that 2 brackets are required for any length of barrier greater than 300mm. For lengths ≤300mm a single bracket must be utilised.
  • All brackets to be suitably fixed to substrate with non-combustible fixings
  • All brackets to penetrate product at mid-thickness.
  • All brackets to penetrate to a depth of 75% of gap width.

Cover Length

  • Butt Joint (RF-CB-BJ and RF-FS-BJ) = 1200mm
  • Rebate Joint (RF-CB-RJ and RF-FS-RJ) = 1175mm
Please advise joint style at time of ordering.

Acoustic Performance

The installation of Siderise RF cavity barrier and fire stop systems substantially enhances the ‘room-to room’ sound reduction of raised access floors which form a continuous common void under adjacent areas. This invariably results in improved speech privacy and greater control of disturbance from intrusive noise. 

The excellent acoustic performance of the RF material is due to the unique internal construction of the stone wool lamella core. Also, the rebated overlap joints, foil facings and the additional sealing of the vertical joints with foil tape all serve to provide improved air tightness. 

Based on laboratory tests to determine airborne sound transmission in accordance with BS EN ISO 140-3 : 1995, BS 2750 : Part 3 : 1995 on a variety of Siderise RF systems the following Weighted Sound Reduction Index (Rw) values can be used: as shown in table 3 below. Sound Research Laboratories Limited test report no. : C/99/5L/7743/I refers. 

Actual performance will be dependent on several factors including the design, choice of materials and degree of fit between components. 

For raised access floor systems requiring higher ‘cross-talk’ values i.e. approx. 45+dB, the improvement in ‘cross-talk’ value may be limited by other factors, including flanking transmission, leakage through M&E systems etc. 

However, for installations offering a reduced ‘cross-talk’ performance, such as installations with frequent service openings, larger improvements can be affected by the installation of the RF before reaching limiting values. In such instances, improvements up to 20dB may be possible.

Table 2 - Acoustic performance

 Weighted Sound Reduction Index   
Product Type Thickness (mm) Rw (dB) 
RF-CB30 75 21 
RF-CB30-X 90 23 
RF-FS60 90 23 
RF-FS60-X 120 25 
RF-FS120 120 25 

Thermal Performance

Thermal conductivity : λ10 = 0.038 W/m.K (tested foil to foil)

Technical Specification

Siderise RF Cavity Barrier and Fire Stop systems

Form supplied Sheet BJ: 1200mm x 1200mm x thickness 
 Sheet RJ: 1200mm x 1175mm x thickness 
 Pre-cut strips: 1200mm x (cavity + compression) x thickness (See Table 1) 
Colour Silver 
Finish Bright aluminium foil 
Density Nominal 75Kg/m3 
Thermal conductivity λ10 = 0.038 W/m.K (tested Foil to Foil) 
Cavities 50mm to 600mm, for voids over 600mm please contact 
Fire resistance 30 to 120 minutes EI to EN 13501-2 
Reaction to fire Class ‘A1’ to EN 13501-1 


Siderise RF Cavity barrier and Fire Stop systems for raised access floors are environmentally friendly. 
  • They contain no Volatile Organic Compounds (VOCs) and no very Volatile Organic Compounds (vVOCs). 
  • Zero Ozone Depleting Potential 
  • Zero Global Warming Potential 
  • Recyclable


Additional Information

The following information is available upon request or via download from the website: 

  • CF 5646 3rd Party Certification
  • NBS Specification Clause 
  • Installation Instructions
  • Safety Data Sheet 

Technical Support

For technical advice or support please contact:

For Installation Training or Site Inspections please contact:


The information in this datasheet is believed to be accurate at the date of publication. Siderise has a policy of continuous product improvement and reserves the right to alter or amend the specifications of products without prior notice. Siderise does not accept responsibility for the consequences of using the products described outside of the recommendations within this datasheet. Expert advice should be sought where there is any doubt about the correct specification or installation of Siderise products.

Published Version: RF_v1_11_2022028_921