Kingspan Kooltherm K103 Floor Insulation Board

Kingspan Kooltherm K103 is a premium floor insulation board designed for use in both solid concrete and suspended timber floor applications. With its ultra-low thermal conductivity of just 0.019 W/mK, it provides exceptional insulation performance — making it an ideal solution for new builds and renovation projects alike. Lightweight, easy to handle, and simple to install, Kooltherm K103 helps you meet your energy efficiency targets without needing thick layers of insulation. Whether you're incorporating underfloor heating or aiming to reduce heat loss through your floors, this high-performance board is a reliable choice.

Key Features

High-performance insulation with thermal conductivity of 0.019 W/mK Allows you to achieve excellent U-values with thinner boards Ideal for both solid concrete and suspended timber floors Suitable for use with underfloor heating systems Lightweight, easy to cut and install Manufactured using premium Kooltherm technology Perfect for both new construction and refurbishment projects BIM objects available for ease of specification

Available Sizes & Coverage

25mm thickness – covers approx. 34.56m² per Pack 40mm thickness – covers approx. 23.04m² per Pack 50mm thickness – covers approx. 17.28m² per Pack 60mm thickness – covers approx. 14.40m² per Pack 70mm thickness – covers approx. 11.52m² per Pack 75mm thickness – covers approx. 11.52m² per Pack 90mm thickness – covers approx. 8.64m² per Pack 100mm thickness – covers approx. 8.64m² per Pack 150mm thickness – covers approx. 5.73m² per Pack

Frequently Asked Questions

1. Is Kooltherm K103 suitable for use with underfloor heating?

Yes, it works perfectly with underfloor heating systems. Its low thermal conductivity ensures minimal heat is lost downwards, making the system more efficient.

2. What makes Kooltherm K103 different from standard insulation boards?

Kooltherm K103 offers premium performance with one of the **lowest thermal conductivity values** on the market. This means you can achieve the same insulation performance using less thickness compared to standard boards.

3. Can I use Kooltherm K103 for both new build and refurbishment projects?

Absolutely. It’s designed to be highly versatile, making it suitable for both **new construction** and **retrofit applications**.

Check out our full range of insulation.

Browse more insulation board available online.

At JJ Building Materials, we're committed to supplying quality building products at competitive prices, backed by the service and expertise you'd expect from an established independent merchant. Whether you're a trade professional managing large-scale projects or a homeowner taking on a DIY renovation, we're here to help you find the right products for the job.

As part of the JJ Roofing Supplies Group, we build on decades of experience supplying construction materials across the UK. We've expanded beyond roofing to offer a growing range of building materials, including timber, insulation, landscaping products, plumbing supplies, flooring, doors, bricks, fencing, garden buildings and much more – all available to order online with nationwide delivery.

We work with many of the industry's leading manufacturers to bring you trusted products that meet the highest standards of quality and performance. Our team is passionate about providing excellent customer service, competitive pricing and a straightforward shopping experience from start to finish.

When you shop with JJ Building Materials, you can expect:

• Competitive prices on leading brands and quality products.
• Nationwide delivery across the UK
  
• A constantly expanding range of building and landscaping materials.
  
• Friendly, knowledgeable customer support.
  
• A trusted business backed by the JJ Roofing Supplies Group.
  

Every order is personally reviewed by our experienced team to ensure everything is correct before dispatch. We offer delivery from as little as the next working day on selected products, so please refer to the dark blue Estimated Delivery box above for the expected delivery timeframe for this item.

We work with trusted manufacturers and specialist delivery partners to ensure your order arrives safely and on time. You'll receive tracking details once your order has been dispatched, and if we need to confirm any delivery details, one of our team will contact you directly to keep everything running smoothly.