In medium to high rise buildings where the external façade is masonry, brickwork may need structural support, typically steel support shelves, but this is often located where a cavity barrier should be positioned.  Installing wall cavity barriers together with masonry support shelves without a detrimental effect on the building’s fire safety can be a challenge.  Now, testing shows this can be achieved with AIM – Acoustic & Insulation Manufacturing’s new Wall Cavity Barrier (Red Edition).

Launched in summer 2024, AIM’s Wall Cavity Barrier (Red Edition) is for use as a cavity barrier or cavity closer within the external wall structure of a building to prevent the passage of heat, flame and smoke within the cavity it fills for 30, 60 or 120-minute fire rating periods.  Due to its extended fire rating, the Wall Cavity Barrier (Red Edition) is intended for use, both vertically and horizontally along fire compartmentation lines, in medium to high rise buildings requiring enhanced levels of fire protection.

In recognition of the challenge of installing a barrier with masonry support shelves, the Wall Cavity Barrier (Red Edition) has been tested with a Leviat designed masonry support shelf indicative of an onerous situation and performed well with cavities up to 300mm. The test configurations were varied to represent varying levels of penetration of the masonry support bracket into the barrier.  The tests confirm that the Wall Cavity Barrier (Red Edition) gives up to 120 minutes EI (Integrity and Insulation).

“The outcome of the testing is that our Wall Cavity Barrier (Red Edition) may be fitted at the top or bottom of the floor slab, with the masonry support shelf tested with a 50% to 140% penetration through the cavity barrier line. This gives the installer much more flexibility in installing both the masonry support shelf and the cavity barrier,” explains AIM’s commercial director Ian Exall.

The testing is in accordance with BS EN 1366-4:2021, recognised throughout the UK and EU as an appropriate resistance to fire test standard for cavity barriers.  Testing also included masonry and steel frame systems (SFS).  AIM has also invested in third party certification from UKAS accredited IFC Certification Ltd in masonry activities.

Wall Cavity Barrier (Red Edition) can be used to fill voids up to 600mm in masonry construction and has been tested in SFS construction and rainscreen cladding.  Supplied in slab form for on-site cutting or cut to size, AIM’s Wall Cavity Barriers are available in 600 and 1200mm wide slabs in 75, 100 and 125mm thicknesses.  They are often used in conjunction with AIM’s Open State Cavity Barriers (OSCBs).

Where the masonry cladding is brick, in order to prevent moisture transgressing the cavity from the brick along the barrier, though unlikely, AIM can supply the Wall Cavity Barrier (Red Edition) with a bonded DPC or can supply the DPC as a separate item.  Both options have been tested and there is no detrimental impact on the fire performance of the barrier.

AIM provides technical, specification, trainin g and on-site support.  New Wall Cavity Barrier (Red Edition) technical literature, including fixing instructions, can be downloaded at: www.aimlimited.co.uk/solutions/wall-cavity-barrier/

Part of the Performance Technology Group, UK-based AIM – Acoustic & Insulation Manufacturing has over 30 years of experience in the design, testing and manufacturing of high-quality fire, thermal and acoustic barriers.  The company produces a wide variety of bespoke insulation products to customer specification and a range of standard products.

www.aimlimited.co.uk