Chelsea Flower Show Perforated Metal for Garden Design

Perforation Perfection

Chelsea Flower Show, Where Perforated Metal Meets Garden Design

Graepels completed this stunning Perforated corten Walkway for Hugo Bugg’s garden in the Chelsea Flower Show 2014. Hugo Bugg’s waterscapre garden was the Gold Medal Winner.

The Perforated Metal Garden Design Project

The Chelsea Flower Show’s one of our most impressive Perforated projects where function and aesthetics fuse to give a truly unique and exciting approach to anitslip flooring. The earthy colour of the Perforated corten panels blend effortlessly with the surrounding landscape.


The design incorporates the geometry of an Iris flower. The perforations are organised into a hexagonal formation. Hugo’s original concept was to have a ‘Picture-Perf’ walkway where an image of dry, broken earth would be punched into sheet metal. The earthy colour of the Perforated corten panels blended effortlessly into its surrounds. At night the walkway was lit from underneath creating a stunning effect as the light dispersed through the perforations.


The design development of each stage was lead by Hugo Bugg, we worked closely with Hugo to ensure his vision could be realised, planning samples, discussing materials and design issues and limitations. The Project required a vast amount of detailed planning, both with the Hugo and Graepels’ own production team, from various drawings to programming, tooling and fabrication. the Graepels Team also provided visual computer generated mock-ups of the images and perforated samples.


Each perforated metal sheet was bespoke and fabricated to the varying dimensions which were required to fit precisely into the garden plan. The panels were a rusty, earthy colour and were sprayed to speed up the ‘weathering’ process of the corten panels. The sheets wer perforated with raised perforations in a hexagonal formation with flush perforations inside the hexagon. Functionally this was to create grip while aesthetically creating the geometry of the Iris flower.


It was imperative that the side of each raised perforation was kept at 45 degrees, keeping each raised perforation height the same to maximise grip. The perforation size needed to be kept to a minimum to facilitate public use, particularly the use high heeled footware. The walkway needed to be light, so as to appear as if it were floating over the garden. This presented a design challenge in how to support the walkway without showing the supports.

Finished Display

Once the sun set and the natural daylight faded, Hugo Bugg’s Garden came to life as the artificial light from underneath the walkway was dispersed through each perforation, lighting up the plush leafy plants and surrounding water.


For ease of installation the Perforated panels were designed, manufactured and assembled in Graepels’ factory before going on to site. The job is a unique combination of Metal and Light. The conceptual design kept the expanse to a minimum to give balance and to complement the overall design.

Concept Development

Hugo Bugg’s original design concept for a ‘Picture Perf’ walkway was to use an image of cracked, dry earth punched into sheet metal, a process known as Picture Perf.

The first step was to find an image that we could work with and manipulate. From here computer generated images were mocked up giving a visual representation of the proposed design.

As the design developed from the concept of broken earth was refocused into another aspect of the design, which can be seen in the water feature the centre area of the garden.


Hugo Bugg’s concept developed from cracked earth into the Iris flower. The Iris flower’s geometry became the sole inspiration for the perforated pattern as which shown clearly in the images. The perforatated metal walkway formaed the main circulation path through the garden. The raised perforations accentuated  the pattern while also providing added grip.

The background pattern was simplified while keeping the original design principles. The geometry of the triangular shaded background is again taken from the geometry of the Iris flower and offers a unique effect particularly when lit up.

As the corten ages the hexagonal formations on the triangular background intensify due to the contrast and shading of the different perforation sizes.


The design development of each stage was lead by Hugo Bugg to ensure his vision could be achieved, planning played an important role.

Samples were key to discovering any design issues and limitations that had not been foreseen in the detailing or planning stages.


The completed job was fabricated in 4mm thick corten, perforated, dimpled and formed into ridged panels with a light skeleton of stiffening ribs which were welded between the perforations at regular intervals across the underside of the walkway.

The ribs were manufactured to exact dimensions in order to slot into the underside of the walkway, between the perforations, so as to remain invisible.

Cantilever legs were fabricated at minimum intervals. Where possible, only one leg was to be used for every joint so as the walkway would appear as if it were floating over the garden.


The panels were perforated using varying dimple sizes and were required to be the same height. Each dimple side was required to retain an angle of 45 degrees to maximise grip.

The perforation diametre was kept to a minimum to facilitate high heeled shoes.

Each panel was leveled for precision and the 74mm flanges were folded using a 30 V in order to give the correct radius on each fold. The folds provided added rigidity making them suitable for up to 1700mm span.

Finished Display

Due to time constraints the natural corrosion processes needed to be sped up, the panels were sprayed evenly with a mixture of chemicals to accelerate the process.

The panels were washed down before being shot blasted, the shot blasting gives a textured finish to the metal which accentuates the perforated pattern of the panels.

The corten steel naturally ages as it is exposed to the climate eventually turning an orange earthy colour before gradually stabilising.

Finished Display

The final element of the Perforated walkway were the lights which were placed around the garden and under the perforated walkway.

LED strips were placed inside the vertical piece of the walkway and in the Sculpture piece. The ‘spike’ lights were placed at regular intervals underneath the Perforated walkway.

Once the sun set and the lights were on the garden came to life with light dispersing through the perforations giving a warm glow to earthy coloured, textured metal.

Finished Display

The orange tone of the panels, once stabilized complement the rich green colours of Hugo Bugg’s stunning garden.

The LED lights gently pick up the perforations in both the dimples and flush perforations. The geometrical pattern is enhanced due to the contrast of the LED lights and textured finish of the metal.


Although the overall expanse of the job is no more than 30 meters, the intricacy and elaborate detail of the pattern, the precision tooling, the engineered design and detailed fabrication required a great deal of time from concept to fruition.

The timescale for this smaller, bespoke project required similar amount of detailing and time as some of the larger scale projects Grapels have worked on. We Thoroughly enjoyed working with Hugo Bugg and all out endevours paid off, as the project won Gold in the Chelsea Flower Show 2014.

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