Siderise RH ‘Open State’ horizontal Cavity Barriers consist of a non-combustible stonewool lamella core, with reinforced aluminium foil faces. This primary seal has a reaction to fire performance to Class 'A1'. The exposed leading edge is also sealed with aluminium foil. Whilst the base material is water repellent and non-hygroscopic, this predominantly enclosed arrangement affords an added degree of weather protection to the core material.

Siderise RH ‘Open State’ horizontal cavity barriers incorporate a continuous high performance reactive intumescent strip which is bonded to the leading edge. The intumescent material has a reaction to fire performance to Class 'E'. In the event of exposure to fire, the intumescent rapidly expands and fully seals the purposely designed ventilation gap formed at the time of installation, between the barrier and the rear of the cladding.

As standard, the range includes a choice of products to suit either 25 mm air gaps - referred to as RH25 - or 50 mm air gaps - referred to as RH50. Both options are available with either galvanized mild steel (G) or stainless steel (S) fixing brackets as part of the system.

The specific horizontal cavity barrier system is then referred to as either RH25G, RH25S, RH50G or RH50S accordingly. The choice of brackets is usually determined by the rainscreen system designer according to project exposure and/or location.

The leading edge of the horizontal cavity barriers is encapsulated in a weather-resistant polymer film. As standard, the film is black to register as a ‘shadow-line’ behind open joints in the cladding.

For product identification purposes, the top edges of the film used on the RH25 and RH50 cavity barriers are colour-coded and labelled to show the product fire performance rating.

Features and benefits:

RH 'Open State' Cavity Barriers are IFC Certified (IFCC 1712)
RH 'Open State' Cavity Barriers allow continuous ventilation and drainage behind the rainscreen envelope
RH 'Open State' Cavity Barriers are tested to ASFP TGD19 ‘Fire Resistance Test of Open State Cavity Barriers’ utilizing BS EN 1363-1 and Principles of BS EN 1366-4
RH 'Open State' Cavity Barrier - (RH25-120/120). provides up to 120 minutes' fire integrity and 120 minutes insulation.
Suitable for horizontal (open void) applications
All RH 'Open State' horizontal cavity barriers are colour-coded for ease of identification.

Fire performance:

Siderise ’Open State’ horizontal cavity barriers have been tested in accordance with ASFP TGD19 (prEN 1364-6): ’Open State’ Cavity Barrier used in External Envelope or Fabric of Buildings. This test method specifies a procedure for determining the fire resistance of ’open state’ cavity barriers when subjected to the standard fire exposure conditions and performance criteria stipulated in EN 1363 Part 1: 2012.
The tests have been undertaken to assess the ability of the horizontal ’open state’ cavity barrier products to reinstate the fire resistance of a pre-cast, 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.
Siderise advise that all ‘RH’ Open State Cavity Barriers are positioned either flush or projecting in front of the thermal insulation.

Product fire performance:

Siderise RH25 ’Open State’ horizontal cavity barrier for maximum 25 mm air gap.

Siderise have tested horizontal cavity barriers with a 25 mm air gap to the ASFP TGD19 method.
During the fire tests, the seals achieved full effective closure in under 5 minutes.
Seal temperatures remained below a 180°C rise during this activation period and maintained the EI requirements for up to E 120 and I 90.
See manufacturers Technical Data Sheet for details.

Siderise RH50 ’Open State’ horizontal cavity barrier for maximum 50 mm air gaps:

Siderise have tested horizontal cavity barriers with a 50 mm air gap to the ASFP TGD19 method.
During the fire tests, the seals achieved full effective closure in under 5 minutes.
Seal temperatures remained below a 180°C rise during this activation period and maintained the EI requirements as detailed in Table 1 for up to E 60 and I 60.
See manufacturers Technical Data Sheet for details.

System fire performance:

Siderise cavity barrier products have been used in several 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 see our website

Please read the below in conjunction with the manufacturer's RH Technical Data Sheet.

Brackets:

Brackets are available in two forms: (G) denotes galvanized steel brackets and (S) denotes stainless steel brackets.
Brackets must be installed at 400 mm centres based on a 1200 mm strip. For lengths ≤800 mm 2no brackets must be used, with spacing reduced pro-rata. Lengths <100 mm should be avoided by cutting down the adjacent barrier accordingly.
All brackets are to be suitably fixed to the substrate with non-combustible fixings.
All brackets to penetrate product at mid-thickness.
Please refer to separate installation instructions and the manufacturers' technical datasheet.

Screw fixings:

Screw fixings must be installed at 400 mm centres based on a 1200 m m strip. For lengths ≤800 mm 2no screw fixings must be used, with spacing reduced pro-rata. Lengths <100 mm should be avoided by cutting down the adjacent barrier accordingly.
All barriers to be suitably fixed to substrate with non-combustible fixings and washers with a 15 mm (maximum) head diameter.
All screw fixings to penetrate product at mid-thickness.
Please refer to separate installation instructions and the manufacturers' technical datasheet.