Sustainable Passive Houses: A Helical Pier Foundation for a Concrete Slab Raft

Client: HMJ Contracts Ltd
Location: Great Bardfield, Essex, England
Project Type: A helical pier foundation for a Passive House’s concrete slab raft

Foundations:

• The installation of 37 helical piers with 3.5” OD (88.9 mm) shaft and a single 18” (45.7 cm) helix for loads up to 16.8 kips (75 kN), and a dual 16-18” (40.6 cm – 45.7 cm) helices for loads up to 22.4 kips (100 kN).

Objective:

• Reduce the amount of concrete used in order to keep the project as low-carbon as possible.

Site Conditions:

• Very soft ground, requiring larger helix diameters to ensure stability.
• Heavy rainfall made the installation process more challenging.

Technical Challenges:

• Selecting the right piers to support the structure on soft ground.
• Managing installation in difficult conditions after prolonged rainfall.
• Completing the installation within just 3 days despite site challenges.

Conclusion:

• The project demonstrated our ability to provide a foundation solution in difficult ground conditions.
• The installation was fast and efficient while also staying on schedule.
• This sustainable project was supported and achieved by minimising the use of concrete while ensuring a strong and durable foundation.