Geofoam

Rigid EPS blocks used as a lightweight structural fill

Download Brochure

A solid block of Expanded Polystyrene (EPS), available in a range of densities

Geofoam is a rigid EPS block used as lightweight structural fill, available in densities ranging from 12 kg to 30 kg/m³. Blocks are supplied in standard sizes of 5025 × 1225 × 525 mm (3.25 m³ per block), with half blocks able to be cut to suit specific project layouts.

Extremely lightweight yet very strong, Geofoam is approximately 100 times lighter than soil and remains chemically inert over long periods. It is a proven, cost-effective alternative to traditional fill, helping to reduce construction loads, improve ground stability, and significantly shorten project timeframes. Geofoam is manufactured to AS1366 Part 3 standards.

Geofoam is widely used worldwide across a range of civil and infrastructure applications, including behind retaining walls, highway and slope stabilisation, bulk filling of large areas, and the construction of ramps, bridges, and embankments.

Its low weight allows for easy handling and rapid installation, while its strength, deformation resistance, insulation performance, and low water permeability make it suitable for demanding structural applications.

Technical Resources

Styrobeck provides a series of technical resources for Geofoam and its installation. Click on a resource to download it.

GeoFoam Resources

EPS Geofoam Blocks - Information

Download this document

GeoFoam Product Brochure

Download this document

EPS Standards - AS1366.3 Physical Properties Table

Download this document

Frequently Asked Questions

Geofoam is a lightweight, rigid, and versatile material made from expanded polystyrene (EPS) foam. It is commonly used in construction and engineering projects as a fill material, insulation, or lightweight structural support. Geofoam is known for its low density, high compressive strength, and ease of installation.

Geofoam offers several advantages:

  • Lightweight: Its low density makes it easy to transport and handle, reducing labor and transportation costs.
  • High Compressive Strength: Geofoam can support heavy loads despite its lightweight nature, making it ideal for use in construction.
  • Insulation: It provides excellent thermal insulation, helping to regulate temperature in various applications.
  • Moisture Resistance: Geofoam does not absorb water, making it suitable for wet or humid environments.
  • Durability: Geofoam is resistant to decay, rot, and deterioration, ensuring a long service life.
  • Environmentally Friendly: Geofoam can be made from recycled materials and is often recyclable.

Geofoam is used in various applications, including:

  • Lightweight fill material: For roads, embankments, and other civil engineering projects where reducing weight is important.
  • Insulation: For foundations, floors, and walls to reduce heat loss or gain.
  • Slope stabilization: To provide support for unstable slopes or embankments.
  • Void filling: To fill voids in construction projects, such as under roads or near retaining walls.
  • Bridge approach fills: To reduce the load on bridge structures during construction.
  • Landfills: For lightweight fill that doesn’t add significant weight or pressure to the ground.

Geofoam is typically installed by stacking the blocks or sheets in place, similar to building with large, lightweight bricks. They can be cut to size on-site using standard cutting tools. The installation process is straightforward and can be completed quickly due to the material’s lightweight nature.

Geofoam has high compressive strength, making it suitable for supporting structural loads. The compressive strength of Geofoam can vary depending on the density of the material, with higher-density Geofoam able to support more weight. It can withstand loads from buildings, roadways, and other structures without significant deformation.

Geofoam can be considered environmentally friendly for several reasons:

  • It is recyclable, and many Geofoam products are made from recycled polystyrene.
  • Geofoam produces fewer carbon emissions during transport compared to other heavier fill materials.
  • It does not decompose, rot, or attract pests, which can help maintain the integrity of the surrounding environment.

However, like any synthetic material, its environmental impact depends on how it is produced and disposed of. Efforts to recycle and properly dispose of Geofoam can help mitigate its environmental footprint.

Yes, Geofoam is moisture-resistant. It does not absorb water, which makes it ideal for use in areas where moisture could cause problems, such as foundations, retaining walls, or road embankments exposed to rain or groundwater.

Geofoam has a long lifespan when used in construction and civil engineering projects. It is resistant to decay, rotting, and biological degradation. As long as it is properly installed and not exposed to harsh environmental conditions like extreme UV radiation or chemicals, Geofoam can last for decades.

Yes, Geofoam is commonly used in road construction, particularly for lightweight fill applications. It helps reduce the weight placed on underlying structures, which can prevent settlement and reduce the potential for soil movement. Geofoam is also used to stabilize embankments, prevent erosion, and provide thermal insulation beneath roadways.

Geofoam itself is not inherently fire-resistant, but it can be treated with fire retardants to improve its fire resistance. Geofoam’s fire resistance depends on the specific material used and any treatments applied during manufacturing. It’s important to verify fire ratings when using Geofoam in applications where fire safety is a concern.

Yes, Geofoam is an excellent material for thermal insulation. It is widely used in foundation systems, floors, roofs, and walls to reduce heat loss or gain. Geofoam provides a high R-value (thermal resistance) per unit thickness, making it highly effective in regulating temperature.

Geofoam is available in various densities and sizes to suit different applications. Common densities range from 15 kg/m³ (for non-load-bearing applications) to 40 kg/m³ or more (for load-bearing applications). The specific density required depends on the project’s load-bearing needs and insulation requirements.

Yes, Geofoam is relatively easy to cut with basic tools such as a hot wire cutter, saw, or knife. Custom shapes and sizes can be cut to meet the specific requirements of a project, and Geofoam can be trimmed or shaped on-site as needed.

While Geofoam offers many benefits, there are some challenges to consider:

  • Cost: Geofoam can be more expensive than traditional fill materials like soil or gravel.
  • UV exposure: If Geofoam is exposed to sunlight for long periods, it can degrade, so it may need to be covered or protected with a UV-resistant layer.
  • Transportation: Although Geofoam is lightweight, large quantities of Geofoam still require careful planning for transportation, especially in remote areas.

Geofoam is safe to handle, as it is non-toxic and does not pose health risks under normal use. However, like any construction material, it is recommended to wear protective gear such as gloves and safety glasses when cutting or handling Geofoam to avoid irritation or injury.

NZ’s Leading Polystyrene Manufacturer

Get in touch with Styrobeck – NZ’s leading manufacturer of precision-cut & moulded polystyrene products.