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GeofoamLightweight Fill

EPS structural fill for embankments, bridge abutments and services trenches — 1% the weight of soil.

Kit complete

Geofoam Lightweight Fill
Technical documentation

The Geofoam Lightweight Fill kit

Brochure, design guide, engineering specification, CAD details and an interactive calculator.

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Product brochureOne-page overview, key specifications, applications.
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Technical design guideFull design guidance, worked examples, standards references.
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Engineering specificationClause-referenced specification text for your tender documents.
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DWG
CAD detailsEditable construction details, SVG.
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APP
Interactive calculatorSize the system and check performance in your browser.
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At a glance

Key specifications

Technopol Geofoam is engineered ultra-lightweight EPS fill (geofoam), supplied as large closed-cell moulded blocks that are field-cut and placed dry without compaction; grade-dependent properties span the EPS12–EPS30 ladder to ASTM D6817 / D7180.

PropertyValueStandard
Product / build-upEngineered ultra-lightweight EPS block fill (geofoam) — large closed-cell moulded blocks, field-cut, placed dry without compaction (~1% the weight of soil)
Density (grade span)12–30 kg/m³
Thermal conductivity (λ) @10 °C0.033–0.045 W/m·K
Design load limit — compressive resistance @1% strain15–100 kPa
Compressive strength @10% strain60–200 kPa
Water absorption< 4 %
Reaction-to-fire class (FR grade)Class B-s1,d0SANS 53501-1
Fire-resistance rating (REI)None — reaction-to-fire classification only; EPS is combustible
Typical block size2500 × 1250 × 950 (typical; other sizes cut to order) mm
Applicable standardsASTM D6817 (physical properties), ASTM D7180 (geotechnical design), ASTM D7557 (sampling)ASTM D6817 / D7180 / D7557

Grade-dependent: density, λ and compressive values span the manufactured grade ladder (Technopol supplies EPS12/SD through EHD/EPS30). Per-grade @1% safe-working loads are 15/17/45/70/100 kPa for EPS12/15/20/24/30. Design sustained stress must stay ≤ the compressive resistance @1% strain (elastic limit); do not design to the @5%/@10% values (creep). The @10% figures are the failure-region strength, not a design load. Fire scope: Class B-s1,d0 applies to FR (flame-retardant) EPS and was established on a 60 mm sheet at ~18.4 kg/m³ (Ignis Test Lab, Cape Town; SANS 53501-1 report 17.08.2023, authorised DJ Streicher Pr Eng). It is not formally extended to every geofoam grade/thickness; standard (non-FR) geofoam is combustible and must be covered by slab, pavement or soil in the permanent works. λ range is the Technopol per-grade datasheet (0.033–0.045 W/m·K, @10 °C); the brochure summary quotes 0.030–0.038 W/m·K. Insulation is incidental — no R/U value per thickness is published for geofoam.

Values from Technopol technical documentation. Confirm the exact figures for your specification with Technopol.

Applications

Where this product is used

The same product does a different job in each of these assemblies — each page states the target, the clause and the limits.

Cold Store & Refrigerated BuildingsUnder-Slab & Slab-Edge InsulationInverted (Protected-Membrane) RoofGeofoam Lightweight Civil Fill

Every number, its source

Performance data & provenance

Each figure is labelled with how we know it — a named in-validity test, a supplier value, an in-house calculation, or a test whose validity has expired.

PropertyValueStandardSource reportStatus
Density (grade span)12–30 kg/m³ASTM D6817Provisional
Thermal conductivity λ @10°C0.033–0.045 W/m·KProvisional
Compressive resistance @1% strain (design limit)15–100 kPaASTM D7180Provisional
Compressive strength @10% strain60–200 kPaASTM D6817Provisional
Reaction-to-fire class (FR grade)B-s1,d0SANS 53501-1IT 23-08-00009Verified

Labels are defined on our data promise; every source report is on the test-report register.

The limits

Where not to use this

A material specified for the wrong job fails you, then us. We would rather lose the order.

Lightweight fill under a fuel-station forecourt, refinery, tank farm, workshop apron or anywhere a hydrocarbon spill can percolate down to the block.
EPS is dissolved on contact by petrol, diesel and aromatic solvents — a single spill can vaporise a section of fill and drop the pavement above it.
→ Lightweight expanded clay aggregate (LECA) or foamed concrete for hydrocarbon-exposed fills, or a fully geomembrane-encapsulated geofoam design signed by the geotechnical engineer.
Embankment or foundation fill where the designer sizes the block on the 10% compressive strength (60–200 kPa, PROVISIONAL, ASTM D6817) instead of the 1% design limit.
Geofoam creeps under sustained load, so the long-term working stress must sit at or below the compressive resistance at 1% strain (15–100 kPa by grade, PROVISIONAL, ASTM D7180) — designing to the 10% figure guarantees long-term settlement.
→ Step up to a higher-density grade, or use conventional/lightweight aggregate fill where the sustained stress is too high. Check the sustained-load case in the free Geofoam Design Checker at ../../products/geofoam/calculator/.
Fill placed below the water table, in a floodplain, or anywhere it can be submerged, without ballast and drainage designed for uplift.
At 12–30 kg/m³ (PROVISIONAL) the block floats — buoyancy, not bearing, governs the design — and long-term immersion lets EPS take up moisture, which adds mass and reduces its thermal resistance.
→ Design ballast/anchorage and a drainage layer for the flood case, or use a non-buoyant lightweight fill below the water table. Model the uplift case in ../../products/geofoam/calculator/.
Where it has been used

Project references

Geofoam Lightweight Fill

Sun International Times Square

Menlyn, Pretoria · Casino / hotel

Geofoam Lightweight Fill

SA Reserve Bank

Institutional / banking

Geofoam Lightweight Fill

Liberty Life

Commercial

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Technical resource

Who should we send this to?

We release technical documentation to named engineers and specifiers so we can support you properly on the project. One entry unlocks everything.

We will not share your details. POPIA compliant.