Case Study: Conquering the Woodbury Slope

When a homeowner in Woodbury, Devon, noticed their patio pulling away from the main house, they were facing a structural nightmare.

The existing patio—built on a massive, reinforced concrete slab weighing nearly 25 tons—was slowly sinking and sliding down a steep 2-meter embankment toward a small, active riverbed.

The traditional fix would have required a massive, deep-foundation concrete retaining wall to hold back the hillside. This meant high costs, heavy machinery risking riverbank collapse, and severe ecological disruption.

Instead, we chose a smarter, low-impact engineering solution: replacing 25 tons of failing concrete with a rigid steel frame anchored by 2-meter ground screws, finished with a block and beam base for a premium porcelain tile finish.

The Engineering Challenge

Building next to water introduces severe soil instability. The original 25-ton concrete slab acted like a heavy sledge, with gravity pulling it down the wet, shifting topsoil.

Furthermore, the client wanted a high-end porcelain tile finish. Porcelain requires an absolutely rigid, zero-flex foundation; any slight movement in the base will crack the tiles and grout.

Our hybrid system solved every hurdle simultaneously:

• 2m Ground Screws: We bypassed the unstable, shifting topsoil entirely. The 2-meter screws cut deep into the dense, untouched load-bearing strata below the failure line of the slope.

• Structural Steel Frame: Instead of timber, which can flex, we mounted a robust structural steel chassis directly onto the screw heads to bridge the slope without sagging.

• Block and Beam Base: To provide the ultra-solid masonry foundation porcelain requires, we laid a suspended block and beam floor across the steel frame.

  
  

The Carbon Accounting: A Massive Win for the Planet

By abandoning the traditional concrete retaining wall and poured slab, this project didn't just save the riverbank—it significantly reduced the project's carbon footprint.

Poured concrete is incredibly carbon-intensive. By replacing mass-heavy concrete with high-strength, lightweight steel and suspended masonry components, we drastically reduced the total material weight, cutting embodied carbon emissions by more than half.

Project Method	Material Mass	Estimated Carbon Footprint
Traditional Concrete Slab & Wall	~40,500 kg	$5,900 \text{ kg CO}_2\text{e}$
Ground Screw, Steel & Beam Hybrid	~8,250 kg	$2,505 \text{ kg CO}_2\text{e}$
Net Savings	32,250 kg saved	3,395 kg $\text{CO}_2\text{e}$ saved

Total Environmental Saving: 3.4 Metric Tonnes of

To put that into perspective, avoiding that concrete retaining wall is the environmental equivalent of driving an average petrol car non-stop for 8,700 miles, or the carbon sequestered by 56 tree seedlings grown for 10 years.

By combining 2m ground screws, a structural steel frame, and a block and beam base, the Woodbury project achieved ultimate stability with minimal impact.

The riverbank's natural drainage remains entirely undisturbed, the local ecosystem is protected, and the client received a rock-solid, premium porcelain patio built to stand the test of time. It proves you don't need to fight nature with tons of poured concrete to build a permanent, beautiful outdoor living space.