Kingspan Kooltherm K3 Floor Board

$ 26.19$ 44.85 p/m2 inc. GST

✓ Commercial Pricing Available

Kingspan Kooltherm K3 boards can be loose laid onto the concrete slab or between the timber joists of a suspended floor.

Actual Area (sq m)
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Kingspan Kooltherm K3 Floorboard Insulation

Kingspan Kooltherm K3 Floorboard is a super high performance, fibre-free rigid thermoset closed cell phenolic insulation core, sandwiched between an upper tissue-based facing and a lower facing of highly reflective aluminium foil 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).

Floor board insulation

  • Super high performance rigid thermoset phenolic insulationKingspan K3 Kooltherm has a Fibre-Free Core
  • Fibre-free, closed cell insulation core
  • Resistant to the passage of water vapour
  • Easy to handle and install floor board insulation
  • Ideal for new build and refurbishment
  • Suitable as a concrete floor insulation
  • Manufactured with a CFC/HCFC-free blowing agent that has zero ODP and low GWP
  • Compliant with AS/NZS 4859.1
  • CodeMark certified
  • FM Approved
  • Group 1 BCA fire classification

Up to 10% of heat is lost through the floor

Did you know you can lose up to 10% of your heat through your floor? Installing floor insulation at the ground level of your house can vastly reduce heat loss and create a more comfortable floor temperature for you and your family to walk on.

A side elevation diagram showing a cavity wall on a ground floor slab with Kingspan Kooltherm K3 Floor Board

Insulation for Concrete Floors and Suspended Ground Floors

Depending if your floor in you home is ground bearing or a suspended floor installation of insulation can vary. For new and existing homes with suspended timbers floors which can’t be accessed from below the floorboards can be removed from above to allow for insulating under floorboards with Kooltherm K3 Floorboard between each floor joist. Kingspan Kooltherm K3 Floorboard is a premium performance rigid thermoset phenolic insulation board for use with solid concrete and suspended ground floors can be placed directly onto the concrete floor. Before the existing floorboards are reinstated a fully sealed vapour control layer is installed above the floor joists, below the floorboards thus making the floor vapour tight and airtight. At all times adequate and unobstructed ventilation must be maintained to the underside of the suspended timber floor joists.

For new houses with which have a solid ground bearing concrete floor construction a continuous damp-proof membrane/radon barrier beneath is required beneath the insulation or below the structural floor slab, taking care to overlap with any damp-proof course in the external walls. Then the premium performance  Kingspan Kooltherm K3 Floorboard can be placed directly onto the damp proof membrane or concrete floor slab. The Kooltherm K3 Floorboard is then overlaid with a separation layer before the installation of the floor screed


Thermal Conductivity (λ-value) 0.020 W/m K (Insulant thickness ≥ 45 mm)
0.021 W/m K (Insulant thickness 25 – 44 mm)
Product Dimensions 2270 mm x 1200 mm (2.72 m2)
Product Thickness 25mm, 30mm, 40mm, 50mm

The Benefits of Kooltherm K3 Floor Slab Insulation in New Constructions:

•    Reduce heat loss through the floor
•    Minimize thermal bridging
•    Make the concrete floor part of the thermal mass of the conditioned space, thereby reducing interior temperature swings.
•    Make your home feel more comfortable and easier to heat.

The Benefits of Kooltherm K3 in Existing Constructions:

•    Will reduce heat loss
•    Help towards reducing energy costs Kingspan Kooltherm Insulation Range
•    Reduce draughts due to the installation of a vapour control layer.
•    Make your home feel more comfortable and easier to heat.

Product Durability

If correctly applied, Kingspan Kooltherm® K3 products can be expected to have a long life of service. Their durability depends on the supporting structure and the conditions of its use. Kingspan Kooltherm® products are warranted for a period of 10 years for both residential and commercial installations.*
* Subject to the terms of the complete Kingspan Kooltherm® warranty document which is available upon request or downloadable from

Product R-Values – Assumption and Key

The thermal calculations are taken through the construction profile with 150 mm concrete slab and Kingspan Kooltherm K3 Floorboard. Kingspan Kooltherm products are manufactured, tested and packaged in conformance with AS/NZS 4859.1. The contribution of the product Total R-values depends on installation and environmental conditions.


Kingspan Kooltherm K3 Floor Board Insulation

Product Thickness Product R-Value
25mm R1.2
30mm R1.4
40mm R1.9
50mm R2.5

Product Information Downloads


25mm (12 boards), 30mm (10 boards), 40mm (8 boards), 50mm (6 boards)