Sentebale – Hope in Vulnerability, known as it is as Prince's Harry's charity, couldn't help but make a splash at RHS Chelsea 2015 preview day. Especially with four senior members of royal family in the garden all at the same time! We show you stunning detail we've had to keep secret in the run-up to the event.

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Photo credit: Jonathan Ward

Footprints! Engraved into the Harvest sawn sandstone underfoot. Not only did these add a very touching detail, but they showed designer Matt Keightley's astonishing attention to detail. During his trip to Lesotho, Matt got some of the children to create painted footprints, which were made into stainless steel templates. These templates were then used to create the footprints on the stone itself.

Once home, Matt had his six-year-old nephew walking, jogging and running so that he could measure the distance between the footprints and space them correctly on the stone. Although they look so small and vulnerable, they give a subtle message of a child's eagerness to enter the Sentebale 'Mamohato Centre' (the inspiration behind the garden), and a rather lovely metaphor for it speeding them on their way in life. Matt Keightley has said that the footprints are intended to evoke the "spirit of playfulness" he encountered during his visit to Lesotho.

It wasn't just a fascinating project for us. It gave us a moment in the limelight. Not long before RHS Chelsea was due to open, the BBC arrived at our Bespoke Stone Centre, near Slough, Berkshire. They wanted to interview Matt and film the processes that would go into producing the paving. Business Development Manager, Craig Potter found himself in front of the camera. Not quite fifteen minutes of fame, but exciting and just a touch nerve-racking...


London Stone's Craig Potter with Matt Keightley, holding the steel footprint templates.

So, how did we do it?

Stage One:

All the materials in the garden were chosen for their resemblance to colours and materials found in Lesotho. Matt's choice of Harvest Sawn Sandstone was no different. His design of large, irregular paving slabs added to the rustic feel and were cut on our CNC saw to match Matt's drawings.

Stone cut on CNC saw

Harvest Sawn Sandstone being cut on CNC saw for Sentebale garden by Matt Keightley.

 Stage Two:

 All the sandstone paving sections were laid out on the factory floor (just as well it's a big one) as they were to be laid in the show garden. At this stage the footprints were also marked on the stone according to Matt's detailed drawing.

Harvest Sawn Sandstone laid out to fit together

Harvest Sawn Sandstone laid out to fit together.

Outline of footprints on Harvest Sawn Sandstone

Outline of footprints marked on Harvest Sawn Sandstone.

  Stage Three:

The stone slabs were then carried to the profiling area, and the edges were fettled by hand. This informal finish helped the stone blend into the rustic character of the setting and is reminiscent of cracked, parched earth. It's not so easy to concentrate when there's a BBC camera crowding in close, but our talented mason, Grant, kept his cool.

The BBC filming the stonemasonry process

The BBC filming the stonemasonry process.

Fettling the edges

Fettling the edges of the stone.

Edges after fettling.

Stage Four:

On the move again, the sandstone paving is taken (carefully) to the shot-blasting area, where the steel templates were held in place while the shot-blasting was carried out. We now had smooth footprints standing out from the textured surface.

Moving slabs to the shotblasting area

Moving slabs to the shot-blasting area.

Shotblasting to create footprints

Shot-blasting to create footprints.

Stage Five:

 To treat the paving slabs, we used Dry Treat Intensifia. This is one of the sealant products we stock because we're very happy with its quality and effect. As well as protecting against stains and water penetration, it enriches the colour of paving.

Sealing and enhancing footprints

Sealing and enhancing footprints.

 Finally, with steel templates again in place, the stone was subjected to a light shot-blasting around the footprints. This emulates the effect of a foot stepping on wet sand, when the colour changes as water is pushed away. It also makes the footprints more prominent.

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Finished footprint. Photo credit: Jonathan Ward

And this was the result. Matt said, “It's better than I had ever hoped for.” After so much planning and collaborating and moments on film, it's hard to believe it's all over. Matt won Silver-Gilt for 'Sentebale - Hope In Vulnerability' and he wasn't the only one who was happy. “Is the boss pleased?” Matt was asked by a passer-by on judging day. “Yes,” he said delightedly.

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Prince Harry being shown around the finished 'Sentebale - Hope In Vulnerability' garden by designer Matt Keightley of Rosebank .  Photo credit: Jonathan Ward

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The completed 'Sentebale - Hope In Vulnerability' garden in the Chelsea sunshine.
Photo credit: Jonathan Ward

The project has certainly kept the offices at London Stone buzzing. Now it's time for a breather, but it can't last long. We've got six gardens to provide stone for at the Hampton Court Flower Show in July...