Kingspan Kooltherm K5 70mm External Wall Board

Kingspan Kooltherm K5 70mm External Wall insulation Board delivers premium thermal performance for masonry wall applications. Built with a fibre-free, rigid thermoset phenolic core, this board excels in external wall insulation systems and thin coat rendering projects.

The 70mm K5 board works seamlessly with both traditional and lightweight polymer-modified renders. Installation happens entirely from outside, allowing you to upgrade existing properties without disturbing occupants.

As one of the slimmest external wall insulation board (EWI) options on the market, it maximises usable internal space—essential when internal insulation isn't practical.

Mineral glass facings are bonded to the insulation core during production, delivering a certified thermal conductivity of 0.022 W/mK. The phenolic core ensures outstanding thermal efficiency whilst using a blowing agent with zero Ozone Depletion Potential (ODP) and minimal Global Warming Potential (GWP).

Kingspan Kooltherm K5 70mm satisfies Building Regulations with exceptional thermal performance in a reduced thickness. It achieves superior insulation values with a thinner profile than EPS, XPS, and mineral wool alternatives.

Each board measures 1200mm x 600mm x 70mm, keeping weight low and installation straightforward.

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: 4.32m2
• 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

Install Kooltherm K5 boards according to manufacturer specifications, which outline comprehensive design and installation guidance. For best performance, attach boards to your substrate (masonry or timber) using Premium Basecoat combined with metal screw mechanical fixings.

After securing boards to the external wall, apply a protective outer layer. Choose either a mortar basecoat or netting cover to guard against excessive heat, moisture, and UV damage. Complete the installation with a protective render topcoat. Consult our full installation guide for comprehensive step-by-step 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: 70mm Aluminium Base Track | 2500mm length profile,
8. Render Beads and Profiles

What is Phenolic Insulation?

Kingspan K5 Phenolic insulation, including our Kooltherm range, ranks among the most thermally efficient insulation materials 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 insulation thickness, making it perfect for high-performance, space-conscious projects.

Info

Explore our full Kingspan Products range and refine by thickness or coverage using the left-hand filters. For project-specific advice or bulk quotations, contact us on +4402038839057, email sales@insulationbee, or use Live Chat for competitive UK Kingspan pricing.