Best Loft & Wall Insulation — PIR Foam Board + Premium (2026)
2 loft & wall insulation matching material “PIR Foam Board” + price “Premium”, hand-picked from UK Amazon listings.
Not sure which one to pick? Read our Best Loft & Wall Insulation UK (2026) guide.
This premium PIR foam board insulation is designed for superior thermal performance in loft and wall applications throughout the UK. Constructed from rigid polyurethane (PIR) foam, it offers a significantly higher R-value compared to standard mineral wool or glass fibre options, contributing substantially to energy efficiency and reducing your heating bills. The closed-cell structure of this PIR board effectively resists moisture ingress, a crucial factor in maintaining insulation performance within damp environments like lofts and exterior walls.
These boards are ideal for creating dense thermal barriers, minimising heat loss through conduction and convection. They’re particularly well-suited for cavity wall insulation, providing a robust and reliable solution where space is often limited. The rigid nature of the PIR foam also makes it easier to cut and fit accurately, simplifying installation compared to more flexible materials.
Designed for professional installers and serious DIY enthusiasts, this premium PIR foam board provides exceptional thermal protection and durability. Remember to consult with a qualified building professional before undertaking any insulation project to ensure compliance with current building regulations and best practices – check Amazon UK for the latest specifications and availability.
#1 Pick
5 X RECTICEL / CELOTEX / KINGSPAN Insulation Board 100MM X 2400MM X 1200MM EURTHANE GP FOIL Back PIR, Silver- PIR Foam Board
- 2400 x 1200 x 100mm, 5 Boards
£374.99
Pros
- Foil-backed PIR board gives a high insulation value for a relatively thin panel
- Supplied as equivalent stock from Recticel, Celotex or Kingspan depending on availability
- 5-board bulk pack suits a full loft, wall or floor insulation project
Cons
- Large pallet-size order needs van access or ground-floor delivery space
#2 Pick
2400 x 1200 x 100mm Celotex GA4100 / Kingspan TP10 / TF70 / Ecotherm Ecoversal Foil Insulation (10)- PIR Foam Board
- 2400 x 1200 x 100mm (10 boards)
£563.00
Pros
- High-performance foil-faced PIR boards for roofs, walls and floors
- Bulk 10-board pack covers a large loft conversion or extension in one order
- Supplied as Celotex, Kingspan or an equivalent brand of identical spec
Cons
- Very bulky pallet delivery needs ground-floor access and someone to help unload
FAQ
What is the R-value of this PIR Foam Board?+
The PIR foam board boasts an R-value of 4.0 (per 100mm thickness), providing excellent thermal resistance. This rating indicates its effectiveness in reducing heat transfer, helping maintain a comfortable temperature within your home.
Is PIR Foam Board suitable for external wall insulation?+
Yes, this premium PIR board is suitable for use in external wall insulation systems when installed correctly and in accordance with manufacturer’s guidance. However, it's crucial to ensure the exterior cladding provides a weatherproof barrier to prevent moisture damage.
How do I cut PIR Foam Board?+
Use a sharp utility knife or saw with a fine-toothed blade for clean cuts. Score the board deeply before applying consistent pressure to avoid chipping and maintain the board’s structural integrity – wear appropriate safety gear.
Does PIR Foam Board absorb moisture?+
PIR foam is closed-cell, meaning it resists water absorption far better than open-cell materials. However, sealing any gaps or cracks with a suitable sealant is still recommended to prevent potential issues.
What tools do I need for installation?+
You’ll typically require a utility knife, tape measure, saw (depending on the required cuts), gloves, and potentially a specialist cutting guide. Ensure you have appropriate safety equipment as well.
Can PIR Foam Board be used in a damp loft environment?+
While PIR foam is moisture resistant, it's crucial to maintain good ventilation in your loft space and avoid direct contact with rising damp. Correct installation practices are vital for optimal performance in a potentially damp area.
What’s the difference between PIR and PUR insulation?+
Both PIR (Polyurethane) and PUR (Polyurethane) offer similar thermal properties. PIR is typically produced using additives that make it more fire-resistant, offering enhanced safety characteristics – this board utilises PIR technology.
How does PIR Foam Board compare to mineral wool insulation?+
PIR foam generally offers a higher R-value per inch than mineral wool, making it more effective at reducing heat loss. However, mineral wool can be slightly more cost-effective for certain applications.
What is the typical thickness available for this PIR Foam Board?+
This premium PIR board is commonly offered in thicknesses ranging from 40mm to 100mm, allowing you to tailor the insulation depth to your specific loft or wall cavity requirements – check Amazon UK for current stock.
What are the fire safety considerations when using PIR Foam Board?+
PIR foam is inherently flame-retardant and classified as Class 1. It’s designed to self-extinguish, preventing the spread of flames. However, always adhere to building regulations regarding fire protection measures.