Meridian House required a full refurbishment of its external decking areas to replace a timber deck podium area which was suspended over an underground car park and a number of balconies with a fully non-combustible system that complies with the latest fire safety regulations. The project included a mix of standard balcony build ups and a complex suspended deck positioned directly above an underground car park.

Some of the balcony areas were straightforward and constructed in the conventional manner. The installers used MetalPad EX adjustable pedestals on a concrete subfloor to support the Wallbarn aluminium joists and Exadeck porcelain deck boards, providing a level and compliant finish.

Other balconies required the aluminium joists to be mechanically fixed to the side of the building structure on one side and to the perimeter of the balcony on the other side, and the decking boards fixed directly to them.

The main podium decking presented a much more difficult set of challenges. This space sat directly and was suspended above the car park and had no concrete slab to support a typical decking system. Instead, the only structural elements available were existing rolled steel joists and beams, and the spans between these were significantly greater than the maximum recommended span of our 100 mm I-Plus aluminium rails when used alone.

The I-Plus rail / joist needed to be mechanically fixed to the steel joists to create a framework on which to install the deck boards. Wallbarn suggested that these should be fixed using our galvanised steel Joist Hanger and holder bracket which was fixed to the steel joists. This method provided a secure and reliable means of supporting the substructure in a refurbishment setting where conventional pedestal systems could not be used.

The project presented an additional technical challenge because the spans between the rolled steel joists exceeded the maximum span that Wallbarn had independently tested them to. These wide gaps meant our standard aluminium joist arrangement would not achieve the required structural performance and deflection would have surpassed the permissible 5 mm. A more robust and sturdy solution was therefore required.

To overcome these constraints, the project architect, Lawtech Group UK Ltd designed a three layer rail and joist substructure using different height Wallbarn aluminium joists. The build-up consisted of a primary layer of 100 mm I Plus Rails, topped with two further layers of 25 mm Box Rails running perpendicular to each other. This created an incredibly strong, interlocked framework capable of carrying higher loads and distributing weight evenly across the suspended area.

Confidence in this approach was supported by independent testing. Wallbarn commissioned load tests with STS, an accredited testing body, to test the maximum span of the I Plus rails when assembled in a framework using perpendicular noggins at intervals along each 3.6 m length to create an H shape framework.

The tests were completed by STS in accordance with BS 8579:2020 using test method 8572:2020. They established the maximum permissible span before reaching the 5 mm deflection limit. The 100 mm I-Plus rail achieved a significantly greater span, approximately 40 percent greater than a single rail alone. This allowed Wallbarn to confirm to the client that the wider spans between the existing steel structure were achievable. The results demonstrated that once assembled as an integrated framework, the system could safely meet structural performance requirements across the large unsupported areas above the car park.

All rails were connected using the full range of Wallbarn right angle and straight brackets and secured with the M8 Wing Nut Kit. Noggins were added throughout to lock the framework into position. Ultra-Low Joist Holders were used where required, alongside other connection options supplied by Wallbarn, to avoid reliance on a single fixing method and to ensure compatibility with the varying conditions found on a refurbishment project. These combined components created a unified and rigid frame with high resistance to lateral movement and consistent performance under load.

The chosen surface finish was the fire rated Class A Exadeck porcelain deck board. Exadeck provides a durable, low maintenance solution with an expected service life exceeding 50 years. Its slip resistance, stain resistance, hard wearing nature and its non-combustible composition made it the appropriate choice for this residential refurbishment where compliance and longevity were essential. The boards were secured using the Wallbarn W Clip hidden fixing system, demonstrating that Wallbarn can supply the complete Class A decking solution including rails, connectors, fixings and accessories to overcome the challenges typical of refurbishment work.

This project presented several technical challenges typical of refurbishment schemes, where existing structures and site conditions can limit conventional solutions. Through adaption, independent testing, good design and a tailored substructure build up, Wallbarn demonstrated that the Exadeck full non-combustible substructure system is flexible and we supported the project team in delivering a fully compliant Class A decking system for both the balcony areas and the suspended deck over the car park.

The completed installation provides a safe, robust and visually luxurious space for residents, with a substructure specifically engineered to manage wide spans without compromising strength, deflection performance or fire safety.