Normal — Cavity Stays Open
The cavity behind the cladding stays open, so ventilation and rainwater drainage continue uninterrupted.
SOLUTION 04
SIDERISE RH Cavity Fire-stopping
A rainscreen cavity barrier that stops fire and smoke spreading through the cavity behind external cladding panels
The Problem
The cavity between external cladding panels (rainscreen cladding) and the building envelope is left open for ventilation and drainage — but in a fire it becomes a channel through which flame and smoke spread rapidly upward.
The Solution
The Siderise RH cavity barrier is made of intumescent material: it keeps the cavity open for ventilation and drainage in normal conditions, and automatically expands in a fire to seal the entire gap, blocking the spread of fire and smoke.
01CASE
What Happens Without Cavity Fire-stopping
In the 2017 Grenfell Tower fire in London (24 storeys), a fire that started inside the building passed through the windows into the cladding cavity and raced across the entire facade, claiming 72 lives. It is cited as the defining example of how missing cavity barriers turn a local fire into a disaster, and it led countries to tighten fire compartmentation of external wall cavities.
02HOW IT WORKS
Open in Normal Conditions, Sealed in a Fire
In Fire — Automatic Sealing
The intumescent strip on the leading edge reacts to heat and rapidly expands to fill the entire cavity, blocking flame and smoke.
03FEATURES
Key Features
Open-State Structure
The cavity stays open in normal conditions, allowing continuous ventilation and drainage behind the cladding.
A1-Rated Non-Combustible Core
A non-combustible stonewool lamella core with reinforced aluminium foil facing delivers an A1 reaction-to-fire rating.
Internationally Fire-Tested
An open-state cavity barrier tested to ASFP TGD 19 (based on prEN 1364-6) and assessed on EN 1363-1 principles.
04LINE-UP
Two Line-Ups Matched to Cavity Width
RH25
Voids up to 25mmOpen-state horizontal barrier maintaining a continuous ventilated void of up to 25mm
RH50
Voids up to 50mmOpen-state horizontal barrier maintaining a continuous ventilated void of up to 50mm
Supplied in 1200mm lengths, pre-cut to the void width · Fire ratings EI30–EI120 (integrity 30–120 min / insulation 30–90 min) · Colour-coded identification tape by rating
05INSTALLATION
Where and How It Is Installed
Under the UK Approved Document B, horizontal (RH) and vertical (RV) barriers are installed at every compartment floor line and around openings such as windows. Barriers are fixed with dedicated support brackets, and joints are sealed with aluminium foil tape.
06DOWNLOAD
Product Brochure
Siderise RH·RV Cavity Barrier Brochure
The official Korean-language brochure covering product construction, rated line-ups, fire test results, and installation guidance.
Korean · PDF · 11 pages · 1.3MB · v4.23 (Nov 2021)
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