Kingspan Insulation Kooltherm K108 phenolic partial fill cavity wall board Celotex Insulation

Kingspan Kooltherm K108

Premium performance rigid Phenolic partial-fill cavity wall insulation board.

Replaces Kingspan Kooltherm K8.

New lower Lambda Value (Thermal Conductivity) 0.019 W/mK... The most thermally efficient commonly used insulating board.

Low emissivity foil facings significantly increase the thermal performance of the cavity.

Boards are designed to fit easily with standard brick and block dimensions allow the insertion of wall ties at appropriate spacing.

Premium performance rigid thermoset fibre-free phenolic insulant.

Unaffected by air infiltration. Resists moisture penetration by allowing a clear cavity to be maintained.

Thicknesses and Availability:

Available in most popular thicknesses from the manufacturer; short lead-times apply as we may need to get the products in from Kingspan before delivering to site.

This Kooltherm Range includes the following readily available product thicknesses: 50mm, 60mm, 75mm and 100mm.

The following thicknesses are manufactured to order and may have minimum order requirements: 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, 70mm, 80mm, 90mm, 110mm, 120mm, 130mm, 140mm and 150mm.

Product Information

General information about Kingspan Kooltherm K108

Product Application

Partial-fill cavity wall insulating board

Kingspans premium performance 'lower-lambda' value phenolic foam board, Kooltherm K108, is suitable for use in partial-fill cavity wall applications.

Product Make-up


Kingspan Kooltherm K108 Cavity Board is a premium performance rigid thermoset fibre-free phenolic insulant.


Faced on both sides with a low emissivity composite foil, autohesively bonded to the insulation core during manufacture.

Product Properties

Thickness 20mm to 150mm
Board Length 2.4m
Board Width 1.2m
Board Edge Square

Product Prices

Buy Kingspan Kooltherm K108

Product ex-VAT inc-VAT
Kingspan Kooltherm K108 50mm, 10 x 0.45x1.2m = 5.4m² £107.17 £128.60
Kingspan Kooltherm K108 60mm, 8 x 0.45x1.2m = 4.32m² £103.54 £124.24
Kingspan Kooltherm K108 75mm, 6 x 0.45x1.2m = 3.24m² £95.81 £114.97
Kingspan Kooltherm K108 100mm, 5 x 0.45x1.2m = 2.7m² £104.22 £125.06
Aluminium Foil Tape 100mm x 50m = 50lm £10.17 £12.20

Limited stock of the most popular boards sizes may be held at some of our larger depots.

Where products need to be brought in from Kingspan, please allow approx. 1 week for delivery on stocked items and up to 3 weeks on made to order thicknesses. While Kingspan keep the majority of the popular thicknesses in stock, less popular thicknesses may carry a minimum order level.

Kingspan reserves the right to change stocked products - while we will do all we can to keep on top of changes, availability and lead times my vary.

  • Generally 1 or 3 working days for delivery
  • Generally 1 to 5 working days for delivery
  • Generally 5 to 10 working days for delivery
  • Special request or made to order item, allow extended lead times. Minimum order levels may apply.
  • Please call to check availability and approximate lead times

Product availability depends upon stock levels at closest depot and delivery logistics to geographic locations

Product Performance and Guides

Product Performance, Manufacturer Downloads, and Installation Guides

Product Performance

Thermal Conductivity 0.019 W/mK
Compressive Strength 120 kPa at 10% compression BS EN 826:2013
Nominal Density 35 kg/m³
Product Thickness Thermal Resistance kg/m²
Kingspan K108 25mm 25mm 1.32 m²K/W 1.09 kg/m²
Kingspan K108 40mm 40mm 2.11 m²K/W 1.61 kg/m²
Kingspan K108 50mm 50mm 2.63 m²K/W 1.96 kg/m²
Kingspan K108 60mm 60mm 3.16 m²K/W 2.31 kg/m²
Kingspan K108 70mm 70mm 3.68 m²K/W 2.66 kg/m²
Kingspan K108 75mm 75mm 3.95 m²K/W 2.84 kg/m²
Kingspan K108 80mm 80mm 4.21 m²K/W 3.01 kg/m²
Kingspan K108 90mm 90mm 4.74 m²K/W 3.36 kg/m²
Kingspan K108 100mm 100mm 5.26 m²K/W 3.71 kg/m²
Kingspan K108 110mm 110mm 5.79 m²K/W 4.06 kg/m²
Kingspan K108 120mm 120mm 6.32 m²K/W 4.41 kg/m²

Product Certificates

Please visit the Kingspan website for product certificates.

Kingspan Videos

How to install insulation in a partial fill cavity