Kingspan Kooltherm K5 50mm External Wall Insulation Board

50mm Kingspan Kooltherm K5 delivers premium external wall insulation performance for masonry wall applications. Built with a rigid thermoset phenolic core that's fibre-free, this board excels in external wall insulation systems and thin coat rendering projects.

The 50mm K5 board works seamlessly with both traditional and lightweight polymer-modified renders. Installation happens entirely from the outside, allowing you to upgrade existing properties without disturbing occupants.

As one of the market's thinnest external wall insulation board (EWI) options, it maximises internal space—perfect for buildings where internal insulation isn't practical.

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

Kingspan Kooltherm K5 50mm satisfies Building Regulations with outstanding thermal performance in a reduced thickness. You'll achieve superior insulation values with a thinner profile than EPS, XPS, and mineral wool alternatives.

Each board measures 1200mm x 600mm x 50mm, delivering lightweight handling and straightforward installation.

Product specification

• Brand: Kingspan
• Model: 50mm K5 Single Board
• Thickness: 50mm
• Length: 1200mm
• Width: 600mm
• Weight: 0.57kg
• Dimensions: 1,200mm x 600mm x 50mm
• 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

Follow the manufacturer's detailed guidelines when installing Kooltherm K5 insulation boards. Secure boards to your substrate—whether masonry or timber—using our Premium Basecoat combined with metal screw mechanical fixings for best results.

After fixing boards to the external wall, apply a protective outer layer. This comprises 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 comprehensive installation guide for detailed 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: 90mm Insulation Panel Fixings Plastic Pin,
6. Metal Fixings: 90mm Insulation Panel Fixings LMX10 Metal Pin Hammer Fix,
7. Base Track: 50mm 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 on the market. A specialised manufacturing process creates a rigid thermoset foam core, positioned 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 the perfect solution for projects demanding high performance and space optimisation.

Info

Explore our complete Kingspan Products range and refine by thickness or coverage using the left-hand filters. For guidance on product suitability for your specific project or to request a quantity discount quotation, contact us via phone on +4402038839057, email sales@insulationbee, or use our Live Chat service for the best UK Kingspan Insulation pricing.