Professional | Lambdaboard




The best possible solution for your insulation requirement, compared to similar products in the market.

LAMBDABOARD is a flexible-faced Polyisocyanurate (PIR) insulation board made on a continuous laminator. The polyisocyanurate cored insulation uses a hydrocarbon-based blowing agent with zero Ozone Depletion Potential (ODP) and complies with the Kyoto Protocol regarding Global Warming Potential (GWP).

LAMBDABOARD offers you the best possible solution for your insulation requirement compared to similar products in the market. LAMBDABOARD is the only product that gives you LTTR Long Term Thermal Resistance.

Regarding fire performance, LAMBDABOARD is a Thermoset material, and unlike Thermoplastic's, it won’t soften, melt or drip when exposed to flames.


8 Reasons to use Lambdaboard

reason 1

Moisture and wind resistant

reason 2

Thermoset, does not melt, drip or spread flame

reason 3

Environmentally friendly & recyclable

reason 4

High compressive strength

reason 5

Aesthetically pleasing

reason 6

Reduces energy usage in a building

reason 7

Superior long-term R-value

reason 8

The right choice for intelligent organs


Technical Information

  • Over Purlin
  • Vertical Cladding
  • Under Screed
  • Cavity Wall
  • Decoboard
  • Inverted Roof
  • Under Soffit
  • Ceiling Insulation
  • Under Purlin
  • Waterproof Membrane
  • Surface Bed
  • Over Rafter/Truss
  • Waterproofing Applications
  • H & T Sections
Take control of your energy costs

In a bid to remain faithful to its mantra, "Take control of your energy costs", Rigifoam recently renewed its commitment to the supply of insulation capable of reducing operational heating and cooling costs resulting in positive environmental and climate change consequences. Its launch product, LAMBDABOARD, is a unique solution to the current energy crisis.

R-Value Performance

LAMBDABOARD has the highest R-value per 25mm thickness, therefore the design R-value of the insulation system can be achieved with a minimum thickness. This in turn allows the overall footprint of the building to decrease and reduces the cost of construction.

Installing Lambdaboard will have positive impact on the HAVC system required, reducing the requirements for over engineered systems, thus having an effect on energy consumption required to run the HAVC system. Putting money back in your pocket.

Board Sizes



  • Obsidian Black
  • Gun Metal Grey
  • DecoBoard
  • White Mineral
  • Mineral Natural
  • Bitumen Kraft
  • Kraft
  • Tile Carrier
  • Eco LamFoil
  • Eco LamFoil 5C
Comparing Lambdaboard with other insulation materials:
Lambdaboard (R-Value m2 K/W) XPS EPS (16/kg per m3) Bulk Fibrous (12/kg per m3)
25mm (1.04) 35mm 40mm 40mm
30mm (1.25) 40mm 50mm 50mm
40mm (1.67) 50mm 60mm 65mm
50mm (2.08) 70mm (30mm + 40mm boards) 80mm 80mm
60mm (2.50) 80mm 100mm 100mm
70mm (2.92) 90mm (40mm + 50mm boards) 120mm 120mm
80mm (3.33) 100mm (50mm + 50mm boards) 130mm 135mm
90mm (3.75) 110mm (80mm + 30mm boards) 150mm Cannot compete
100mm (4.17) 125mm (60mm + 65mm boards) 170mm (80mm + 90mm boards) Cannot compete

* when using a double layer board, fire compliance is comprised, the labour costs to install the boards are also doubled. *

Equivalent thickness comparing R-Values.

Spec Your Project Here

Benefits of using Lambdaboard


aesthetic light

Rational Design

energy saving
Proven reduction in energy consumption


labour saving




moisture resistance
On cavity wall and under screed installations


moisture resistance
On vertical cladding and under screed installations


high compressive


cell content
-30°C - 120°C


long term thermal

Test your building with Lambdaboard

thickness dial temperature indicator
Test the temperature in your office

Obtain estimates for your potential energy savings and the projected temperature variances between outdoor and indoor environments.

These estimations are based on various configurations of Lambdaboard® insulation in a hypothetical scenario without the presence of an HVAC system or roofing insulation.

Furthermore, you can anticipate reduction in your energy expenses, stated in Rand per square meter, on an annual basis by incorporating Lambdaboard® insulation whilst aligning with the SANS 10400 XA ED2 regulations.

For any guidance, please reach out to our rational design department.

Please be aware that the provided information relies on simulated theoretical data generated through the use of Agrement software - BISMAC, in accordance with the relevant South African National Standard.


Lambdaboard Thickness

0 mm

Actual outside temperature

31° C

Calculated inside temperature

Annual energy usage (kWh)

Annual energy savings (kWh)

Rand saving per annum as per the Eskom rate





map map 1 map 2 map 3 map 4 map 5 map 6 map 7 map 8


  • Zone 1
  • Zone 2
  • Zone 3
  • Zone 4
  • Zone 5
  • Zone 5h
  • Zone 6
  • Zone 7
Spec Your Project Here Fire Report Tox Test

The regulations were designed to counter act the dramatic climate change and the degradation of the planet. The South African Government promulgated the SANS 10400 XA building codes, in order to reduce greenhouse emissions These regulations are designed to reduce energy usage and pollution in the built environment.

Lambdaboard has a proven R-Value and a Long-Term Thermal Resistance (LTTR) and will outlive the life span of the building, reducing the future building envelope’s energy consumption and demand, compared to similar thermoplastic products in the market.

Lambdaboard is a member of PIMA (Polyisocyanurate Manufactures Association) with has a proven track record in LTTR and sustainability.

Lambdaboard provides 30% saving energy consumption. 70% of heat loss can be found in the roof of a structure. Lambdaboard can reduce this by 100% so that no heat is lost via the roof structure.

Energy Consumption (kWh/m²) vs Energy Demand (VA/m²)

Energy Consumption (kWh/m²)

Rational Design Building using Lambdaboard

Energy Demand (VA/m²)
Winter Indoor Temperatures (NO HVAC Equip)

Connect with us