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Siderise RV | Cavity Barriers for Cladding / Rainscreen – Vertical – Technical Data

Version: 2.01 - Release Date: September 2023


Siderise RV vertical cavity barriers for rainscreen cladding are used to full fill the void between the external envelope and internal structure.

The construction offers excellent resistance to the passage of both smoke and fire. Additionally, by fully sealing the void, they assist ventilated façades to function by maintaining air-pressurisation compartmentation.

Significantly, their unique stonewool lamella core construction enables the vertical barriers to accommodate the serviceability movement normally associated with rainscreen façades.

Intersections between horizontal and vertical cavity barriers are simply abutted, with RFT 120/45 foil tape applied as detailed in the RV Installation Instructions. The leading edge compresses directly against the external envelope. No intumescent strip is required.

Product Description

Siderise RV vertical cavity barriers for rainscreen cladding applications consist of a non-combustible stonewool lamella core, with reinforced aluminium foil faces.

Siderise RV vertical cavity barriers are installed within the cavity formed between the rainscreen facade and the inner structural wall using appropriate Siderise support brackets. Brackets are available in either galvanised mild steel (G) or stainless steel (S).

The standard product length is 1200mm

Fire Performance

Reaction to Fire – Siderise RV vertical cavity barriers have third party certification with Intertek and are classified as A1 to EN 13501-1. Please see Table 1 for further information.

Table 1 : Reaction to Fire Performance

Certificate Number WHI-09/02-22-000001-02 (UK)
WHI20-32944302 (US) 
Thickness Range 50-175mm 
Substrates Mechanically fixed to gypsum or any other A1 or A2-s1,d0 substrate 
Joints With or without joints 

Resistance to Fire - Siderise RV vertical cavity barriers have been tested in accordance with EN 1366-4: 2006+A1: 2010. The cavity barriers maintained integrity (E) and insulation (I) requirements as detailed in Table 2.

The tests have been undertaken to assess the ability of the vertical-cavity barrier products to reinstate the fire resistance of a lightweight aerated concrete supporting construction. This is the standard assembly for testing such cavity barrier products as it allows the performance of the individual barrier to be classified.

Third-Party Certification

For full details of Siderise RV certified products, including the testing and scope of our Third-Party Certification, please refer to Certifire Certificate Number CF 6028 and IFC Certification IFCC 1712 Please see Table 2 for more information.

'Certifire certification and any product label is only applicable to the specific scope and field of application as defined within the current and valid Certifire certificate number CF 6028. Any additional details, amendments or additions to the product, or any use outside the scope or field of application, outside of that stated within Certifire number CF 6028 has not been reviewed or approved by Warringtonfire.'

The Certificates are available for download from our online Technical Resources or by contacting our Technical Support department:

Table 2: Resistance to Fire Performance

Product type Thickness
Void range (mm) Compression
Integrity (mins) Insulation (mins) 3rd Party Approval 
RV-90/30 75 20 - 50 +10% 90 30 CF 6028 &
IFCC 1712 
RV-90/30 75 51 - 450 +10mm 90 30 CF 6028 &
IFCC 1712 
RV-90/60 90 20 - 50 +10% 90 60 CF 6028 &
IFCC 1712 
RV-90/60 90 51 - 450 +10mm 90 60 CF 6028 &
IFCC 1712 
RV-120/120 120 20 - 50 +10% 120 120 CF 6028 &
IFCC 1712 
RV-120/120 120 51 - 450 +10mm 120 120 CF 6028 &
IFCC 1712 

Please note: -

Integrity and Insulation ratings in the above tables refer to performance in product fire tests to EN1366-4:2006+A1: 2010.

In all cases, we recommend that the specifier and user review the specific project configuration regarding available large-scale system test data and in light of the latest National Building Regulations, local Building Code, and/or government advice. For voids greater than 450mm, please contact our Technical services team for further information. 

Table 3: Support Brackets

Product Type Voids (mm)         
20-50 51-150 151-240 241-300 301-450 
RV-90/30 N/A B65/110 B195 B355 B355 
RV-90/60 N/A B65/110 B195 B355 B355 
RV-120/120 N/A B65/110 B195 B355 B355 

Support Brackets

Support brackets should be installed at 600mm fixing centres (300mm from each end).

The brackets are supplied as standard in 1mm galvanised mild steel (G) or stainless steel (S), in a flat form for site folding. They incorporate pre-notched indents to aid this process.

Lengths of the barrier are secured with these dedicated brackets, which impale the product at mid thickness to a depth of 75% of void.

The brackets are drilled on-site and secured to the inner structural wall using non-combustible steel anchors or screws. These fixings are not supplied by Siderise.

Please see separate installation instructions and installation video available on our website.

Please note:

For voids up to 50mm: (measured cavity) +10% compression is required.

 For voids greater than 50mm: (measured cavity) + 10mm compression is required.

Siderise RH horizontal cavity barriers are installed so that they terminate each side of the Siderise RV vertical cavity barriers.

System Fire Performance

Siderise cavity barrier products have been used in a number of large-scale system tests such as BS 8414(1&2) and NFPA 285. These may be used to evaluate the performance of the Siderise cavity barriers within a complete cladding system. The rules for the evaluation of results from BS 8414 are subsequently defined in BS 9414. 

For information regarding performance and assembly details in system tests please contact our technical services team. 

Thermal Performance

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

Technical Specification

Table 4: Siderise RV vertical cavity barriers

Property Value 
Form Supplied Sheets : 1200mm x 1200mm (UK and EU); 1200mm x 1150mm (RoW);
Pre-cut strips: 1200mm long and supplied in width to suit advised void size. 
Colour No colour. Stonewool exposed to leading edge 
Finish Aluminium foil to surfaces exposed to cavity 
Density Nominal 75 kg/m3 
Thermal Conductivity λ10= 0.038 W/m.K (tested foil to foil) 
Void sizes RV-90/30 permissible for voids up to 450mm 
 RV-90/60 permissible for voids up to 450mm 
 RV-120/120 permissible for voids up to 450mm 
Reaction to Fire Class ‘A1’ to EN 13501-1 see Table 1 
Resistance to Fire For product fire performance see Table 2 


  • Stonewool core is recyclable

Additional Information

The following information is available upon request or via download from the website: 
  • Safety Data Sheet
  • Product Brochure

  • Standard Details
  • Installation Instructions
  • Installation Video
  • NBS Specification Clauses

Technical Support

Technical Services Team: 

Site Services Support

Siderise offers a range of services to contractors and installers. These include toolbox product installation and site installation inspection and reporting (subject to availability and by agreement). 

Site Services Team:


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.

Siderise Group Forge Industrial Estate, Maesteg, UK, CF34 0AY T: +44 (0)1656 730833 F: +44 (0)1656 812509 E: W:

Published Version: RV _v2_01_20230926_1334