Transforming Harrods’ former helipad into an exclusive rooftop events space presented significant technical challenges, from uneven roof levels to stringent fire safety requirements. Total Contractor looks at how Wallbarn’s Class A fire-rated substructure and porcelain decking system helped deliver a safe, stable and luxurious finish.
Revamping an existing flat roof is rarely a straightforward process, even more so when it’s atop a super high profile building in a capital city, and forms an integral part of a new ultra-exclusive private rooftop events space.
That was the challenge facing the project team working on the transformation of Harrods Helideck on the roof of the iconic department store in Knightsbridge, London.
The helipad was identified as the perfect location for a new high-end pavilion building with accompanying outdoor terrace, opening up the space for exclusive brand activations, private dining events and celebrations – all with sweeping skyline views of the city.
But with floor heights varying by up to 400mm across the flat roof and the need to deliver a fully compliant Class A fire-rated decking and substructure solution that was ultra strong, ultra hardwearing and with a refined, luxurious appearance, the challenge was on. Substructure and decking specialist Wallbarn stepped up, as managing director Julian Thurbin explained: “The key challenges were to propose a solution that complied fully with fire safety regulations, dealt with the roof falls, worked perfectly as a retrofit on a heritage building and complemented the new pavilion building. It had to be sympathetic to the culture of the building whilst also being ultra high luxury.”
That solution was Wallbarn’s complete Class A fire-rated substructure paired with partner company Fire Deck’s non-slip, non-scratch, non-stain Exadeck wood finish porcelain decking boards.
Substructure
The flexibility of Wallbarn’s I-Plus aluminium rail system, combined with the secure fixing capability of its adjustable MetalPad Ex steel pedestals (protected by Zintec 200 anti corrosion coating), allowed falls across the roof to be evened out and a completely flat, stable substructure prepared for the Exadeck boards.
Technically difficult ramped sections required aluminium rails cut to precise angles and cross-fixed to form a rigid substructure. With the 60mm wide aluminium joists providing the foundation, Exadeck boards were then secured using Wallbarn’s Class A ‘W Clip’ fixing system.
To provide roof deck access points across the 550m2 space, box frames were fitted into the Wallbarn substructure and topped with Exadeck, delivering the all-important flush finish.
Stack bond design
Achieving a totally aligned and flat surface was also project-critical because the design team had chosen a stacked bond layout for the decking boards – visually striking but significantly more demanding to achieve, with even slight misalignment being highly noticeable. The Exadeck boards, being rectified on two planes, achieved the required look with ease. Rectification involves two additional manufacturing processes to ensure the side and underside planes of each board are perfectly straight, preventing movement and rocking. This double-rectification process, combined with Wallbarn’s perfectly flat substructure, meant that perfect alignment of the stack bond layout was achieved. Exadeck’s consistent dimensions and tight tolerances simplified installation further.
Deck strength
Given the deck is a public space, strength of both the substructure and decking was of paramount importance. MetalPad Ex steel pedestals, which range in height from 26mm to 375mm and can be supplied with a self-levelling option, are independently tested to a weight tolerance of more than five tonnes per unit. The I-Plus rails are also independently tested.
“Our system stands out for a number of reasons,” said Julian. “The substructure is very strong, we’ve tested everything. We take nothing for granted and we do not self certify, the system is independently tested and will not move if installed correctly.
“Pairing our Class A substructure with Exadeck porcelain decking delivered a finish with the performance, looks and absolutely necessary style for the Harrods scheme. The finished project is effortlessly elegant, strong and fire-safe.”
Conclusion
Delivered by a highly experienced team – Kendall Kingscott led the architectural design with TC&D Construction acting as specialist contractor – this technically ambitious project delivered the flawless finish expected of an iconic, ultra-luxury project. Working in partnership, Wallbarn and Fire Deck supported TC&D Construction throughout, offering layout options, technical guidance, site visits and responsive delivery coordination to ensure a smooth installation and on-time completion.