Polystyrene Sheet | ThermaSlab
Thermaslab EPS Insulation Sheets for Multi-Application Construction Systems
EPS Sheets for multiple purposes
Building Product Information SheetThermaslab is Expol's versatile range of expanded polystyrene (EPS) insulation sheets engineered for use across a wide variety of construction applications. Available in multiple grades and densities, Thermaslab is designed to deliver reliable thermal performance, design flexibility and structural stability in projects where space limitations, performance requirements and long-term durability must all be balanced.
Suitable for slabs, walls, roofs and general construction use, Thermaslab allows specifiers and builders to achieve high R-values in both tight and open building spaces, providing an efficient insulation solution without compromising build integrity or design outcomes.
Multiple Grades for Flexible Performance Requirements
Thermaslab is available in a range of grades to suit different structural loads, environmental conditions and insulation performance needs, allowing precise specification based on application and design intent.
High R-Value Insulation for Restricted and Open Spaces
Designed to perform in both constrained and standard cavity conditions, Thermaslab achieves superior thermal results in situations where insulation thickness may be limited.
Structural Stability & Long-Term Durability
Thermaslab delivers consistent dimensional stability and compressive performance designed to maintain insulation effectiveness and structural integrity over the life of the building.
Key Features & Benefits
Why Choose ThermaSlab?
Cost-Effective Solution
Affordable insulation without compromising on quality, providing excellent value for residential projects.
Residential and Commercial Applications
Specifically designed for residential and commercial use, delivering reliable performance for homes and smaller projects.
Easy Installation
Lightweight and easy to handle, making installation quick and straightforward for contractors and DIY enthusiasts.
Learn more about specific applications
Click a solution below to view installation guides and full system details
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Technical Data
| Properties / Test Method / Standard | SL | S | M | H | VH |
|---|---|---|---|---|---|
| Material | Expanded Polystyrene | ||||
| Density | 12 kg / m³ | 16 kg / m³ | 20 kg / m³ | 24 kg / m³ | 28 kg / m³ |
| Usage | Underfloor Insulation | Wall Insulation | Concrete Slab Insulation | Concrete Slab Insulation | Concrete Slab Insulation |
| Sheet Size | 2400 mm x 1200 mm | ||||
| Thickness / R Value | |||||
| 10mm | - | - | - | - | - |
| 20mm | - | R 0.53 | R 0.54 | R 0.56 | R 0.57 |
| 25mm | - | R 0.66 | R 0.68 | R 0.69 | R 0.71 |
| 30mm | - | R 0.79 | R 0.81 | R 0.83 | R 0.88 |
| 35mm | - | R 0.92 | R 0.95 | R 0.97 | R 1.00 |
| 40mm | - | R 1.05 | R 1.08 | R 1.11 | R 1.14 |
| 45mm | - | R 1.18 | R 1.22 | R 1.25 | R 1.29 |
| 50mm | - | R 1.32 | R 1.35 | R 1.39 | R 1.43 |
| 55mm | - | R 1.45 | R 1.49 | R 1.53 | R 1.58 |
| 60mm | R 1.46 | R 1.58 | R 1.62 | R 1.67 | R 1.71 |
| 65mm | R 1.59 | R 1.71 | R 1.76 | R 1.81 | R 1.86 |
| 70mm | R 1.71 | R 1.84 | R 1.89 | R 1.94 | R 2.00 |
| 75mm | R 1.83 | R 1.97 | R 2.03 | R 2.08 | R 2.20 |
| 80mm | R 1.95 | R 2.11 | R 2.16 | R 2.22 | R 2.29 |
| 85mm | R 2.07 | R 2.24 | R 2.30 | R 2.36 | R 2.43 |
| 90mm | R 2.20 | R 2.37 | R 2.43 | R 2.50 | R 2.57 |
| 95mm | R 2.32 | R 2.50 | R 2.57 | R 2.64 | R 2.72 |
| 100mm | R 2.44 | R 2.63 | R 2.70 | R 2.78 | R 2.86 |
| 110mm | R 2.68 | R 2.89 | R 2.97 | R 3.06 | R 3.14 |
| 120mm | R 2.93 | R 3.16 | R 3.24 | R 3.33 | R 3.43 |
| Thermal Conductivity (ATSM 168) | K – Value 0.41 | K – Value 0.038 | K – Value 0.37 | K – Value 0.036 | K – Value 0.035 |
| Rate of water vapour transmission (max) - Measured parallel to rise at 23°C (AS 2498.5) | 630 mg/m²s | 520 mg/m²s | 520 mg/m²s | 460 mg/m²s | 400 mg/m²s |
| Permeability m/s | - | - | - | - | - |
| Compressive Resistance (AS 2498.3) | at 1%: - KPA | at 1%: 34 KPA | at 1%: 49 KPA | at 1%: 64 KPA | at 1%: 88 KPA |
| at 2%: - KPA | at 2%: 59 KPA | at 2%: 96 KPA | at 2%: 108 KPA | at 2%: 142 KPA | |
| at 5%: - KPA | at 5%: 74 KPA | at 5%: 111 KPA | at 5%: 133 KPA | at 5%: 172 KPA | |
| at 10%: 70 KPA | at 10%: 84 KPA | at 10%: 126 KPA | at 10%: 146 KPA | at 10%: 189 KPA | |
| Young's Modulus | - | 3.8 MPA | 4.1 MPA | 6.2 MPA | 8 MPA |
| Cross breaking strength (AS 2498.4) | 135 KPA | 165 KPA | 200 KPA | 260 KPA | 320 KPA |
| Dimensional stability (max) - Length, width & thickness at 70°C for 7 days (AS 2498.6) | 1% | ||||
| Long term water absorption by immersion (ASTM C72) | - %v / v | ||||
| Determination of flame propagation surface ignition (AS 2122.1-1993) | Medium flame duration (max): 2 sec | ||||
| Eighth value: 3 sec | |||||
| Fire behavior (AS/NZS 1530.3:1999) | Spread of flame index (0-10): 0 | ||||
| Smoke developed index (0-10): 5 | |||||
| Recycled Content | 30% | 5% | 0% | 0% | 0% |
| Recyclability | EPS is 100% recyclable | ||||
| Environmental Statement | EPS is inert and non-toxic. There are no chemicals or gases harmful to the environment emitted from EPS either during manufacture or within use. | ||||
| Ozone Depleting Potential | EPS does not contain ozone-depleting CFC or HCFC gases, nor use them in its manufacture. As a result, EPS has zero ozone depletion potential. | ||||
| Vermin Resistance | EPS does not offer any nutritive value | ||||
Warranty & Compliance
Warranty and New Zealand Building Code information as published in the ThermaSlab family technical data sheet.
| Specification | Detail |
|---|---|
| Warranty | 20-year warranty on EXPOL EPS foam insulation products |
| NZ Building Code clauses | Clause B2 Durability B2.3.1(a), B2.3.1(b); Clause E3 Internal moisture E3.3.1; Clause F2 Hazardous building materials F2.3.1(a) |
| Energy efficiency | BRANZ, H1 Energy efficiency performance H1.3.1(a), H1.3.2(e) |
| Building Act 2004 | EXPOL EPS is not subject to a warning or ban under the Building Act 2004 |
For full warranty details see the Warranty page, or download the technical data sheet above.