A new intumescent cavity barrier solution for use in rainscreen cladding systems has been launched by Promat UK. The PROMASEAL® RSB-V and RSB-N barriers form part of the Promat PROMASEAL® Fire Stopping Range, and provide architects, specifiers and contractors with a new option when it comes to creating effective fire protection for rainscreen cladding.
Rainscreen cladding systems generally involve large, continuous cavities in the outer leaf of the building, which can create a ready route for fire and smoke. PROMASEAL® RSB-V and RSB-N have been introduced to address this issue. They allow the creation of either a ventilated or non-ventilated fire protection cavity barrier which is both effective and reliable. Both PROMASEAL® RSB-V and RSB-N feature a rock wool section with an integral intumescent strip. When exposed directly to fire, the intumescent material expands rapidly to fill the gap in the rainscreen, thus preventing the spread of the fire along the cavity.
Promat PROMASEAL® RSB-V features a continuous intumescent strip on the edge of the rock wool barrier, and is designed for use in horizontal applications. A 25mm air gap is usually required between the edge of the cavity barrier and rear of the external cladding material, thus creating the required ventilated air space whilst still providing the necessary fire performance. On contact with fire, the intumescent strip expands and seals the ventilation gap.
Promat PROMASEAL® RSB-N is intended for vertical applications. It incorporates a continuous length of Promat PROMASEAL® expansion joint strip on the edge of the rock wool barrier, which allows the barrier to be fully compressed onto the rear face of the external cladding. This eliminates any possibility of gaps occurring that may allow fire and smoke to travel along the cavity.
PROMASEAL® RSB-V and RSB-N are available in different widths and pre-cut units, to suit cavity depths ranging from 50mm up to 450mm. This makes them easy to install and suitable for a wide range of applications. Fitting brackets are supplied with these products.
Both can be specified with complete confidence, having been successfully assessed for up to 60 minutes (integrity and insulation), using the principles of BS476 Part 20: 1987, WF Assessment report 316419.
