CitiDeck® non-slip timber decking from Marley has been used in a £5m refurbishment project at Clifford's Tower in York, for which Marley won a WPA award. The decking has been installed in a freestanding roof deck which provides spectacular 360° views across York. It will help ensure the safety of visitors, and provide a natural and attractive surface.
Building the roof deck required careful planning, both to preserve the historic structure and to ensure the new elements were structurally sound. This meant building a completely new timber structure inside the tower.
Four enormous glulam columns were installed to provide support for the timber deck. They also form the basis for the internal walkways and staircases that provide access to the upper levels of the tower.
The non-slip timber deck itself was constructed using Marley CitiDeck®. The decking was installed, and carefully cut to a smooth curve following the line of the new metalwork guarding at the edge. There is also a large opening in the middle that allows visitors to look down to the floor of the keep. The boards were also used to create seating areas and the guard structure around the central opening.
“We chose CitiDeck because we needed an attractive and robust anti-slip timber decking for use in high-traffic public areas,” explains an architect at Hugh Broughton Architects Ltd, who worked on the project. “We wanted a consistent appearance between the deck boards, and the timber boards forming the sides to the benches and perimeter guarding, and CitiDeck made that possible."
With high numbers of visitors to the tower, safety was a top priority. “It’s great that CitiDeck boards perform very well in testing when both wet and dry,” the architect said.
According to the Health and Safety Executive, flooring is considered to have a low slip potential if it achieves pendulum test value (PTV) of at least 36. CitiDeck has been extensively tested, and has far exceeded the minimum, with PTVs of 61 when wet and 73 when dry.
Durability and ease of maintenance were also important considerations for the external and exposed public rooftop area. The smooth profile of the boards was an especially attractive feature, as it reduces the likelihood of grit getting trapped in any grooves. It also means that the decking can be easily cleaned by brushing, as there’s no water source available at the roof deck level.
Sustainability was another important consideration. While a variety of decking products were considered, including composite boards. Timber was ultimately chosen due to its sustainability credentials.
“Timber was preferable due to it being a natural material,” the architect explains. Marley’s CitiDeck is sourced from managed forests that are PEFC or FSC certified, so specifiers can rest assured that it is an environmentally-friendly product.
The architect also noted that timber has the potential for repurposing at the end of its lifespan: “There are more options for recycling the boards at the end of their usable life”.
Award winning project
Marley won Preservative Treated Wood Project of the Year through The Wood Protection Association for this project. Awarded for the use of CitiDeck anti-slip decking construction at Clifford's Tower.
Supplied by English Heritage.