DRIVING MARKET LEADING PRODUCTS: PROMOTING BUILDING SAFETY

George Danzey-Smith, Commercial Manager at ARC Building Solutions, explores the issues created by overspecification of cavity barrier products and introduces a new innovation – TCB Square.

For 15 years, ARC Building Solutions has been bringing unique and innovative cavity barrier products to market, cementing themselves as industry experts and contributing to the delivery of safer and more sustainable homes and buildings. However, a shifting trend in recent times has seen overspecification of products as a ‘knee jerk’ reaction to heightened regulation.

The Golden Thread and overspecification

With the introduction of the Building Safety Act in 2022, underpinned by The Golden Thread, there is greater emphasis on building safety and regulation than ever before. While the importance of these regulatory changes cannot be underestimated, there are still challenges to address, not least with the issue of overspecification.

Our job is always to get the right product, into the right hands and installed correctly, that’s how you maximise building safety. However, we are seeing a shifting trend towards product overspecification. Increasingly, we see installers and contractors specifying what is perceived to be the best performing overall product, often at greater expense, with less consideration of the specific context in which the product is being installed.

In general, overspecification is a reflection of a desire in the industry to be risk averse, with greater scrutiny and external pressure bringing higher risk of liability. While not a problem in itself – as inevitably this means higher standards of care and accountability – it does mean that the right products are still not necessarily finding their way into the right applications. In simple terms, good cavity barrier specification is about specifying the right product for the right application.

ARC TCB Square

With this in mind, in March 2023 ARC launched its latest product innovation, the TCB Square. A brand new, easy to install and robust cavity barrier for timber frame construction. The TCB Square is specifically designed to fit around penetrations through the external wall in low rise housing, offering up to 60 minutes of fire integrity.

We’re really excited to be launching the TCB Square, our new cavity barrier specifically targeting pipe penetrations in timber frame construction. The TCB Square is designed to be compression fitted where there will be a pipe penetration, fixed through the flanges at the point where the pipe penetration will be in the timber frame structure. Once the service penetration has been drilled and the service pipe installed, a hole is cut on the protective polythene packaging and the product is placed over the pipe. The exterior brickwork can then be laid creating the cavity and compressing the ARC TCB Square to its required fit and securing the product in place.

The problem of overspecification certainly extends to this market, where linear barriers are frequently specified and used to ‘box in’ or ‘wrap’ the pipe. This is one of the problems ARC TCB Square is designed to eliminate.

The aim of any cavity barrier product, first and foremost is containment and compartmentation, maximising the amount of time occupants have to evacuate a building. Different types of cavity barrier offer advantages, ensuring their suitability for their intended applications. At present, it is not uncommon for linear barriers to be used in place of specialist products in the application of pipe penetration. These products however, by their very nature, require some adaptation to fit this purpose. Linear barriers in this context, must be cut to size, with cut sections used to ‘box in’ or ‘wrap’ the pipe. Of course, this creates problems for specification.

Linear barriers are not specified for this purpose and as a result, intended performance cannot be guaranteed. The box section requires great care and attention on-site to achieve a correct installation. If lengths are cut incorrectly, or any small gaps are left exposed, the fire performance of the product could be entirely compromised.

Equally, wrapping linear cavity barriers around the pipe can also be detrimental to performance. Any bending of a linear mineral wool cavity barrier before or during installation can cause the fibres to tear, resulting in reduced performance. It might be the case that some of these linear products offer higher rating of fire integrity and insulation. However, where usage falls outside of the certified scope, whatever performance benefit may have existed can be undone in installation.

Reducing the margin for error

This was one of the driving forces behind the development of the TCB Square. Specifically designed to perform the function of a cavity barrier around openings in the wall, TCB Square is a far more robust and safer solution than linear cavity barriers. Of course, the TCB Square must also be specified correctly, with accurate measurements of the cavity and designed widths essential to achieving design intent. However, there is far less margin for error with a specialised product. It is worth noting that this is not a penetration seal product or ‘fire stop’ and does not replace the requirement for such products where one exists. Instead, TCB Square aims to bring a safer cavity barrier solution to market.

Exceeding the technical requirements of Approved Document B, the TCB Square has been tested in accordance with the principles given in EN1366-4, achieving up to 60 minutes fire integrity within a timber frame construction.

The key message that cannot be emphasised enough, is that the ‘best’ solution is the one that minimises the potential for performance gaps to occur once the solution has been installed and people start to use the building. In this context, more care must be taken across the industry to specify the correct solution, for the correct application. Only then can greater and more consistent standards of building safety be achieved.

www.arcbuildingsolutions.co.uk

IMAGES: 01-03. When specified correctly TCB Square is a far more robust and safer solution than linear cavity barriers