Kooltherm K8
Cavity Board

Kooltherm K8 Brick Outer Block Inner Drywall

Partial Fill Cavity Wall Insulation

Kingspan Kooltherm K8 Cavity Board is a premium performance insulation product, with a fiber–free rigid thermoset phenolic core, faced on both sides with a low emissivity composite foil facing which is used for insulation in partially filled cavity walls.

  • Higher R–value per inch than any commonly used insulation
  • Negligible smoke developed
  • Clear cavity is maintained – resists moisture penetration
  • Low emissivity foil facings significantly increase the thermal resistance of the cavity
  • Unaffected by air infiltration
  • Safe and easy to install – no irritative fibers produced
  • Zero ODP, low GWP, HCFC and CFC free

Product Information

Property Test Method Result
Nominal Thickness
(in / mm)
1.58 / 40
1.97 / 50
2.36 / 60
Standard Dimensions
Width (in / mm)
Length (in / mm)
47.25 / 1200
16 / 406.4
Compressive Strength, Min.
ASTM C 209 15
Water Absorption, Max.
(% by volume)
ASTM C 272 1.15
Density, Min.
ASTM C 1621 2.0
Closed Cell Content
(% of cells closed)
ASTM D 6226 94.67
Air Permeance
(L/S/m2) / (cfm/ft2)
ASTM E 2178 0.002 / 0.000
Water Vapor Permeance, Max.1
ASTM E 96 0.51
Fire & Smoke
Flame Spread
Smoke Developed
ASTM E 84 25

Permeance shown is for 25mm thick board. Permeance typically decreases as board thickness increases.
*Contact Kingspan Insulation for available non-stock sizes.

The R–values detailed below are quoted in accordance with ASTM C 518 (Standard Test Method for Steady-State Thermal Transmission Properties by Means of the Heat Flow Meter Apparatus).
Insulant Thickness Thermal Resistance
(in) (mm) (R-value)
1.18 30 9.5
1.38 35 11
1.57 40 12.5
1.77 45 14.5
1.97 50 16
2.17 55 17.5
2.36 60 19
2.56 65 20.5
2.76 70 22
2.95 75 24
3.15 80 25.5
3.35 85 27
3.54 90 28.5
3.74 95 30
3.94 100 31.5
4.72 120 38
5.91 150 47.5
* Refer to Kingspan Insulation for current stock and non–stock sizes.
Kooltherm K8 Cavity Board Brochure

Kooltherm K8 Cavity Board Brochure

Kingspan Kooltherm K8 Cavity Board_Submittal_US_IMG

Kooltherm K8 Cavity Board Submittal

TER 1601-06

Technical Evaluation Report 1601-06 NFPA 285 - Kooltherm Insulation Board

TER 1601-07

Technical Evaluation Report 1601-07 NFPA 286 - Kooltherm Insulation Board

TER 1603-04

Technical Evaluation Report 1603-04 - Kooltherm Insulation Board Exterior Wall Coverings Attachment

Kooltherm Safety Data Sheet

Kooltherm Safety Data Sheet

Kingspan Kooltherm Section 07 21 00 Building Insulation

Kingspan Kooltherm Section 07 21 13 Phenolic Insulation


CSI 3-Part Specifications

Click the link below to view our CSI 3-Part Specs from ARCAT in a variety of file formats.

Kingspan Insulation CSI 3-Part Specifications

View and Download the Specifications

Kooltherm Insulation Board 15 Year Thermal Warranty

Kooltherm Insulation Board 15 Year Limited Thermal Warranty

Warranty Registration Form 1708 - Interactive_Page_1

Kingspan Warranty Registration Form


BIM Objects / CAD Details

Click the link below to view our BIM Objects / CAD Details from ARCAT

Kingspan Insulation BIM Objects/CAD Details from ARCAT

Download Typical Wall Assemblies

Featured Project / Case Study

Do you need assistance planning your project?

Our teams are dedicated to helping make the process as easy as possible and ensure you get the right materials for your needs.

Contact Us

Kingspan Insulation North America

Head Office & Sales Office – North America

Kingspan Insulation LLC

2100 Riveredge Parkway, Suite 175

Atlanta, Georgia



Call: +1(800) 241 4402

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