Kingspan Kooltherm K5 70mm External Wall Insulation Board

70mm Kingspan Kooltherm K5 delivers premium thermal performance for masonry wall applications. This rigid thermoset phenolic insulation board combines exceptional efficiency with a fibre-free construction, making it ideal for external wall insulation systems and thin coat rendering projects.

The 70mm thickness provides outstanding thermal resistance whilst maintaining a slim profile, preserving valuable internal space. Installation occurs entirely from the exterior, allowing work to proceed without disrupting building occupants. Compatible with both traditional and lightweight polymer-modified renders, these boards suit a wide range of external wall configurations.

Manufactured with mineral glass facings bonded to the phenolic core, this external wall insulation board achieves a thermal conductivity of 0.022 W/mK. The phenolic core employs a blowing agent with zero Ozone Depletion Potential (ODP) and minimal Global Warming Potential (GWP), delivering environmental responsibility alongside performance.

Compared to EPS, XPS, and mineral wool alternatives, the K5 board achieves superior thermal values with reduced thickness. Each board measures 1200mm x 600mm x 70mm, weighing just 0.57kg for straightforward handling and installation.

Product specification

• Brand: Kingspan
• Model: 70mm K5 Single Board
• Thickness: 70mm
• Length: 1200mm
• Width: 600mm
• Weight: 0.57kg
• Dimensions: 1,200mm x 600mm x 70mm
• Board Coverage: 0.72m2 per board
• Pack Coverage: 0.72m2
• Pack Quantity: 1 board
• Compressive Strength: 100kPa
• Density: 35kg/m3
• Thermal Conductivity: 0.022 W/mK
• R-Value: 2.50m2K/W
• Material: Rigid thermoset phenolic insulation
• Profile: Square edge
• Colour: Light shade of red
• Fire Classification: Euroclass C-s2,d0
• Finish: Mineral glass coatings
• Application Temperature: from +5 °C to +25 °C
• Applications: External insulation for masonry walls
• BBA Certified: Yes
• Features: Thinnest commonly used External Wall Insulation Board
• Manufacturer: Kingspan Kooltherm® K5

Application

Installation should follow the manufacturer's comprehensive guidelines, which detail design and application procedures. Secure boards to the substrate (masonry or timber) using Premium Basecoat and metal screw mechanical fixings for best performance.

Once fixed to the external wall, protect the boards with an outer layer—either a mortar basecoat or netting cover—to guard against excessive heat, moisture, and UV damage. Complete the installation by applying a protective render topcoat. Consult our full installation guide for comprehensive instructions.

Storage Instructions

Shelf Life: Refer to the manufacturer's expiry date. Storage Conditions: Store in a dry location, in the original packaging, and away from excessive heat or UV light.

Applications

• · External wall insulation systems:
• · Solid brick and block walls.
• · Cavity block and brick walls.
• · Thin coat rendering.
• · Cavity brick walls.
• · Cavity dense block walls.
• · Insulated render systems.
• · Steel-framed walls
• · Timber-framed walls.

Kingspan Kooltherm K5 Installation

We recommend

1. Adhesive and Base-Coat Render: EWI-225 Premium Basecoat Render Adhesive 25kg,
2. Rendering Mesh: Orange Fibreglass Rendering Mesh Roll,
3. Priming Paint: EWI-333 Top Coat Primer,
4. Top Coat Thin Coat Render: EWI-075 Silicone Render.
5. Plastic Fixings: 120mm Insulation Panel Fixings Plastic Pin,
6. Metal Fixings: 120mm Insulation Panel Fixings LMX10 Metal Pin Hammer Fix,
7. Base Track: 120mm Aluminium Base Track | 2500mm length profile,
8. Render Beads and Profiles

What is Phenolic Insulation?

Kingspan K5 Phenolic insulation represents some of the most thermally efficient insulation available today. A specialised manufacturing process creates a rigid thermoset foam core sandwiched between two facing layers, such as low-emissivity composite foil.

Phenolic insulation enables you to meet demanding U-value targets with minimal thickness, making it perfect for projects demanding high performance and space optimisation.

Info

Explore our complete Kingspan product range, filtering by thickness or coverage using the left-hand menu. For guidance on product suitability for your project or to request a quantity discount quotation, contact us by phone on +4402038839057, email sales@insulationbee, or use Live Chat for the best UK Kingspan insulation prices.