Flooring Insulation Boards

Floor insulation boards at trade prices – PIR, Kingspan Kooltherm K103 phenolic, XPS and EPS – for solid concrete, suspended timber and screeded floors, delivered to England and Wales.

Which floor insulation?

  • PIR boards (Kingspan Thermapitch TP10, Recticel Eurothane GP), 2400 × 1200mm, 25–150mm: the usual choice under screed or between/over joists, λ 0.022 W/mK.
  • Kingspan Kooltherm K103 phenolic floorboard, 25–150mm: the thinnest option for the same U-value, useful where floor height is limited.
  • XPS (Kingspan GreenGuard GG300, Jackon Jackodur KF 300), 1250 × 600mm, 30–150mm: high compressive strength and moisture resistance for below-slab, heavy-duty and inverted applications.
  • EPS 70, 100 and 150, 2400 × 1200mm, 25–150mm: economical boards – the higher the number, the higher the compressive strength.

Under a screed, lay a separating layer and perimeter edge strip, and check the manufacturer's loading guidance. To size a PIR floor board, use our PIR U-value calculator.

Delivery: prices are ex VAT. We deliver to England and Wales free on every order, with a £400 ex VAT minimum order.

Underfloor insulation on a concrete slab: lay PIR, Kooltherm K103 or EPS boards with a damp proof membrane, then screed. In a suspended timber floor, cut boards to fit tightly between the joists. Our PIR thickness guide shows what thickness you need for floors, walls and roofs.

What thickness of PIR do I need? Check your floor, wall or roof against Building Regulations (Part L) targets with our free U-value calculator. Open U-value calculator

67 products

Did you know that up to 20% of a building’s heat can escape through the floor? By installing high-performance floor insulation, you can significantly reduce this heat loss and see a noticeable reduction in your heating costs. For instance, underfloor insulation for wooden floors could save an average household around £60 annually. This makes insulation boards an essential investment in both comfort and cost savings.

Flooring insulation boards are a versatile option, suitable for timber, concrete, and suspended floors, as well as basements and garage floors. These boards are an excellent addition for customers incorporating underfloor heating systems, as they optimise heat distribution and retention. Their seamless performance makes them perfect for refurbishment projects and new builds alike.

Insulating your floors doesn’t just lower energy bills; it also improves sustainability. With insulated floors, you can significantly improve your home’s thermal performance, achieving better U values and lowering your carbon footprint by up to 240kg per year. This makes our insulation boards an eco-friendly option for energy-conscious homeowners and contractors.

When you opt for materials like PIR and extruded polystyrene, you’re choosing boards that are built to endure. With a lifespan of 20 to 50 years, they provide lasting warmth and energy efficiency. Moisture-resistant features ensure durability in areas like basements and garage floors, particularly when paired with a damp-proof membrane.

A well-insulated floor retains heat longer, keeping indoor spaces warm and cosy throughout the winter months. Underfloor insulation also contributes to acoustic insulation, minimising noise transfer between levels. Whether you’re insulating a family home or a multi-storey property, these benefits enhance overall liveability.

If you’re incorporating underfloor heating systems into your project, insulation boards are an indispensable addition. PIR and polystyrene boards are highly effective at directing heat upwards, maximising the efficiency of your underfloor heating while reducing energy consumption. Whether you’re installing heating beneath tiles, timber floors, or floating floors, these boards are ideal for achieving optimal results.

We proudly stock leading brands, including Kingspan, Recticel, and EcoTherm, known for their exceptional quality and innovation. These brands offer a wide range of options tailored to underfloor heating systems and general floor insulation needs. With materials like mineral wool and closed-cell foam, you’re guaranteed top-tier insulation performance.

Floor insulation boards are designed for ease of installation, with features like tongue-and-groove joints ensuring a snug fit. For timber floors, rigid insulation panels fit neatly between joists, minimising drafts. A damp-proof membrane can further enhance the boards’ performance, especially for areas prone to moisture, such as ground and garage floors.

Insulation boards aren’t just about warmth – they also act as a barrier against moisture, protecting timber joists and floor coverings from damage. By pairing these boards with a damp-proof membrane, you can prevent long-term issues like rot, making them ideal for properties in damp-prone areas such as ground floors or basements.

No matter what your project requires, you’ll find insulation boards in a variety of thicknesses, catering to different U value requirements and applications. From new construction to upgrades in existing properties, these lightweight and user-friendly boards are an indispensable part of any energy-efficient flooring solution.