Kooltherm K3 Floorboard

Product Code


Insulation for Solid Concrete Ground Based Floors

Kingspan Kooltherm K3 Floorboard is a high performance, fibre-free rigid thermoset closed cell phenolic insulation core, sandwiched between two layers of tissue based facing autohesively bonded to the insulation core during manufacture.

Kingspan Kooltherm K3 Floorboard is manufactured without the use of CFCs/HCFCs and has zero Ozone Depleting Potential (ODP) and low Global Warming Potential (GWP).

  • Made in Australia
  • Resistant to the passage of water vapour
  • Easy to handle and install
  • Fibre-free core

Product Data
Declared Thermal Conductivity(λ-Value) 0.021 W/m.K at 23oC
(insulant thickness ≥ 45 mm)
0.023 W/m.K at 23oC
(insulant thickness 25 – 44 mm)
Product Dimensions 2400 mm x 1200 mm (2.88 m2)
Product Thickness 25, 30, 40, 50 mm

Assumption and Key

The thermal calculations are taken through the construction profile with 150 mm concrete slab and Kingspan Kooltherm® K3 Floorboard. The R-values shown are Total R-values for the building element as required by the Energy Provisions of the National Construction Code, calculated in accordance with AS/NZS 4859.1:2002 Amdt.1.

Kingspan Kooltherm® products are manufactured, tested and packaged in conformance with AS/NZS 4859.1:2018.

Product R-values

Nominal Product Thickness Declared Product R-value at 23oC
25 mm R1.10
30 mm R1.30
40 mm R1.75
45mm R2.15
50mm R2.35

Solid Residential Concrete Slab on Ground Floor – Insulation below the Floor Slab

System R-value

Product Thickness Heat Flow Out
25 mm RT1.4
30 mm RT1.6
40 mm RT2.1
50mm RT2.7

Specification Clause

The floor insulation shall be Kingspan Kooltherm K3 Floorboard ___ mm thick, with a tested smoke obscuration of not more than 100m2/kg, comprising a CFC/HCFC–free and zero Ozone Depletion Potential (ODP) rigid thermoset phenolic insulation core with a tissue based facing on both sides, manufactured under a management system certified to ISO 9001:2015, ISO 14001:2015, OHSAS 18001:2007 and ISO 50001:2011 by Kingspan Insulation Pty Ltd and shall be installed in accordance with the instructions issued by them. A Project Specific Warranty provided by Kingspan Insulation must be submitted.


Specify with:

Handling & Storage

Installation should be in accordance with AS 3999:2015, Section 4 – Safety Requirements for Insulation Installation.

The packaging of Kingspan Kooltherm should not be considered adequate for outdoor protection. Boards should be stored inside a building. If, however, temporary outdoor storage cannot be avoided then the boards should be stacked flat on a level base, clear of the ground, and completely protected from inclement weather through use of a polythene sheet or weatherproof tarpaulin. Boards that have been allowed to get wet should not be used.

Resistance to Solvents
The insulation core is resistant to short-term contact with petrol and with most dilute acids, alkalis and mineral oils. However, it is recommended that any spills be cleaned off fully before the boards are installed. Ensure that safe methods of cleaning are used, as recommended by suppliers of the spilt liquid. The insulation core is not resistant to some solvent-based adhesive systems, particularly those containing methyl ethyl ketone. Adhesives containing such solvents should not be used in association with this product. Damaged boards or boards that have been in contact with harsh solvents or acids should not be used.

Kingspan Insulation products are chemically inert and safe to use. A Product Safety Information Sheet is available from Kingspan Insulation Pty Ltd.

Please note that the reflective surfaces on this product are designed to enhance their thermal performance. As such, the will reflect light as well as heat, including ultraviolet light. Therefore, if these boards are being installed during bright or sunny weather, it is advisable to wear UV protective sunglasses or goggles and if the skin is exposed for a significant period of time, protect bare skin with a UV block sun cream.

Installation must be in accordance with AS 3999 Bulk Thermal Insulation Installation and AS 3000 Electrical Installations (Wiring Rules).


Cutting should be carried out either by using a fine toothed saw, or by scoring with a sharp knife, snapping the board over a straight edge and then cutting the facing on the other side. Ensure accurate trimming to achieve close-butting joints and continuity of insulation.

Solid Concrete Ground Based Floors – Insulation below the Floor Slab

Compressive Loads
Un–reinforced floor screeds can be used in conjunction with Kingspan Kooltherm K3 Floorboard in most applications. However, where floor loads are to be excessive, please contact our Technical Services Department on 1300 247 235 or email technical@kingspaninsulation.com.au.

Kingspan Kooltherm K3 Floorboard is not recommended for use in direct contact with subsoil and must be used over a DPM. Where vertical slab edge insulation is required, the DPM should always be placed on the external face of the Kingspan Kooltherm K3 Floorboard.

Wheeled / Foot Traffic
Ensure boards are protected during installation from wheeled / foot traffic by using scaffold planks or other protective measures.

Installation Instructions

  • The site should be prepared and foundations, where appropriate, built to damp proof course (DPC) level.
  • A thin sand blinding may be used to achieve a continuous level surface free from projections over rolled aggregate.
  • The damp proof membrane (minimum 300 micron / 1200 gauge polythene) should be laid with joints well lapped and folded, to prevent the passage of ground water, over well compacted aggregate, prior to laying Kingspan Kooltherm K3 Floorboard.
  • The membrane should be brought up the surrounding foundation walls/slab until it is sufficiently above the height of the wall DPC so that it will connect with or form the DPC.
  • Kingspan Kooltherm K3 Floorboard should not be placed under any direct point loads or foundations including slab thickening.
  • The insulation boards should always be loose–laid break– bonded, with joints lightly butted.
  • If two layers of Kingspan Kooltherm K3 Floorboard are required, they should be horizontally offset relative to each other so that, as far as possible, the board joints in the two adjacent layers do not coincide with each other. To avoid glare, lay with the foil face facing down.
  • Insulation boards should be overlaid with a polythene sheet (not less than 125 micron / 500 gauge) as best practice, to prevent the wet concrete penetrating the joints between the boards, and to act as a vapour control layer. Ensure the polythene sheet has 150 mm overlaps, taped at the joints.
  • The subsequent installation of the concrete slab and screed or other flooring material is carried out in a manner similar to that for an un–insulated floor. The concrete slab and screed should be allowed to dry out prior to the installation of the floor finish.

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Project Specific Warranty Download
CAD PDF – Solid Concrete Ground Floor Below Floor Slab Download
CAD DWG – Solid Concrete Ground Floor Below Floor Slab Download
BIM 2016 – Kooltherm K3 Floorboard Download
BIM 2017 – Kooltherm K3 Floorboard Download
BIM 2018 – Kooltherm K3 Floorboard Download
BIM 2019 – Kooltherm K3 Floorboard Download
PSI – Kooltherm Range Download

Management Standards

Standard Management System
ISO 9001:2015 Quality Management
ISO 14001:2015 Environmental Management
ISO 45001:2018 Health and Safety Management
ISO 50001:2011 Energy Management


Product Testing

Characteristic Standard Result
Compressive Stress AS 2498.3 Typically exceeds 120 kPa at 10% compression
Water Vapour Resistance BS EN 12086:1997 / I.S. EN 12086:1998 > 35 MN·s/g

Fire Performance

Test Test Method Result
Flame Spread
Heat Release
Smoke Release
AS 1530.3 Spread of Flame Index: 0
Smoke Development: ≤ 3


Environmental Data Table

Aspect Characteristic
Recyclability Non-contaminated insulation site waste is recyclable, but there are currently no facilities in Australia to process returned material
Re-usability Re-usable if removed with care (long term of service expected)
Water Use No water used in Kingspan Insulation’s manufacturing process
Blowing Agent Global Warming Potential (GWP) Manufactured with a blowing agent that has low GWP
Blowing Agent Ozone Depletion Potential (ODP) Manufactured with a CFC/HCFC-free blowing agent that has zero ODP
Packaging Contains 0% recycled product
Polythene wrap and EPS skids 100% recyclable