Celotex PIR Insulation Board | 2400mm x 1200mm | (All Sizes)

CelotexSKU: IUK00001

Sale price£15.60 

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Celotex PIR Insulation Boards


Discover the exceptional thermal efficiency of Celotex PIR Insulation Boards, designed to meet your diverse insulation needs. 

Celotex PIR Insulation boards are multi-purpose insulation boards, with high-performing energy efficiency and thermal conductivity.

Celotex PIR Insulation is an easy-to-install polyisocyanurate (PIR) insulation board with excellent thermal performance, featuring a low emissivity foil facing.

Celotex insulation boards come in a range of thicknesses from 20mm to 200mm, it can be considered for floor, wall, and roof applications.

Whether you're upgrading your home or constructing a new space, Celotex offers an insulation solution that combines high-performance with easy installation.


Key Features

  • Multi-Purpose Utility: Ideal for roofs, walls, and floors across various settings.
  • Superior Thermal Performance: Features a thermal conductivity of just 0.022 W/m.K, minimizing insulation thickness while maximising efficiency.
  • Range of Thicknesses: Celotex PIR Insulation boards are available from 20mm up to 200mm, tailored for specific applications.
  • Easy Installation: Lightweight and rigid, these boards simplify transport and fitting.
  • Certified Quality: BBA certified (Certificate 17/5405) for use in pitched roofs, dry lining, and floor insulation applications.


Product Specification








Lambda Value




TB4000 20 2400 1200 0.022 0.9
TB4000 25 2400 1200 0.022 1.1
TB4000 30 2400 1200 0.022 1.35
TB4000 35 2400 1200 0.022 1.55
TB4000 40 2400 1200 0.022 1.8
GA4000 50 2400 1200 0.022 2.25
GA4000 60 2400 1200 0.022 2.7
GA4000 70 2400 1200 0.022 3.15
GA4000 75 2400 1200 0.022 3.4
GA4000 80 2400 1200 0.022 3.6
GA4000 90 2400 1200 0.022 4.05
GA4000 100 2400 1200 0.022 4.5
XR4000 110 2400 1200 0.022 5
XR4000 120 2400 1200 0.022 5.45
XR4000 130 2400 1200 0.022 5.9
XR4000 140 2400 1200 0.022 6.35
XR4000 150 2400 1200 0.022 6.8
XR4000 165 2400 1200 0.022 7.5
XR4000 200 2400 1200 0.022 9.05

Fire Classification

Euroclass F Reaction to Fire classification, according to BS EN 13501-1. Products with this level of classification are not provided with a rating for smoke emission.


Understanding the Celotex PIR Insulation Board Range

When selecting Celotex PIR Insulation Boards, you have three primary options to consider: Celotex TB4000, Celotex GA4000, and Celotex XR4000.

What is the difference between Celotex TB4000, GA4000, and XR4000?

The key distinction lies in the thickness of the boards, tailored to accommodate various insulation needs across different building applications.

  • Celotex TB4000 offers thicknesses ranging from 20mm to 40mm. This range is specifically engineered for applications requiring minimal build-up to meet thermal requirements, making it ideal for areas where space conservation is essential, such as internal wall insulation and overcoming thermal bridging.
  • Celotex GA4000 is available in thicknesses from 50mm to 100mm. It is designed for a broad range of applications, providing a versatile solution for walls, floors, and roofs that require standard insulation thicknesses for effective energy conservation and compliance with building regulations.
  • Celotex XR4000 extends from 110mm to 200mm in thickness, suited for projects demanding superior thermal insulation performance. This series is perfect for high-specification build projects where enhanced thermal resistance is critical, such as in advanced roofing systems and ground floors subjected to high heat loss.



Celotex PIR Insulation boards are versatile and can be used in a wide variety of applications including:


  • Pitched Roof Insulation - Between and Under Rafters
  • Flat Roof Insulation - Balconies and Terraces
  • Flat Roof Insulation - Between and Under Joists


  • External Wall Insulation - Upgrading Cavity Walls
  • External Wall Insulation - Timber Frame Walls
  • External Wall Insulation - Solid Walls


  • Ground Floor - Beam and Block Floors
  • Ground Floor Insulation - Concrete Slab Ground Floors
  • Ground Floor Insulation - Upgrading Concrete Slab Floors
  • Ground Floor Insulation - Suspended Timber Floors


Why Choose Celotex?

  • Environmental Performance: The TB4000 series achieves a BRE Green Guide Rating of A, supporting your BREEAM assessments.
  • Enhanced Fire Safety: Euroclass F fire rating ensures safety without compromising on performance.
  • Innovative Facer Technology: Low emissivity foil facing boosts thermal performance in sealed cavity air spaces.


Frequently Asked Questions About PIR Insulation

What is PIR insulation? PIR (polyisocyanurate) insulation is a type of thermal insulation material used in building and construction. It is known for its excellent thermal performance and high resistance to heat flow, making it an effective solution for reducing energy costs in homes and buildings.

Why is PIR Insulation so expensive? The cost of PIR insulation reflects its superior thermal performance and energy efficiency. The materials and technology used to manufacture PIR insulation are advanced, contributing to its higher price point compared to other insulation types.

Can PIR Insulation get wet? PIR insulation is generally moisture-resistant but not entirely waterproof. While it can withstand some exposure to moisture without losing its insulative properties, prolonged or excessive wetness can affect its performance. It's important to protect PIR insulation from water during installation and use.

Can PIR Insulation be recycled? Recycling PIR insulation can be challenging due to its chemical properties and the presence of fire retardants. However, efforts are being made to improve the recyclability of PIR products as part of the industry's commitment to sustainability.

How much PIR Insulation do I need? The amount of PIR insulation required depends on the specific energy efficiency goals, climate, and the area being insulated. It's best to consult with a professional to calculate the optimal thickness and quantity based on your particular needs.

How is PIR insulation made? PIR insulation is manufactured through a chemical reaction between a polyol and an isocyanate, forming a rigid foam board. This process involves the use of catalysts and blowing agents, which expand the material into a highly insulative foam with a closed-cell structure.

How does PIR Insulation work? PIR insulation works by trapping air within its closed-cell foam structure, significantly reducing heat transfer. This air barrier effectively minimizes the amount of heat that can pass through, helping to maintain a consistent indoor temperature and reduce energy consumption.

What is PIR Insulation made of? PIR insulation is made from polyisocyanurate, a type of plastic known for its excellent fire resistance and thermal properties. It typically features a foil facing to enhance its thermal resistance and moisture barrier.

Where to buy PIR insulation? PIR insulation is available at InsulationUK! We stock a wide range of PIR insulation products from leading brands such as Recticel, Ecotherm, Kingspan, and Xtratherm.

How to cut PIR Insulation? PIR insulation can be cut using a sharp knife or a fine-toothed saw to fit specific measurements.

For precision cuts and to minimize onsite waste and mess, InsulationUK offers a bespoke cutting service. Customers can order PIR boards pre-cut to their exact specifications, ensuring a perfect fit and easier installation.


Key Considerations

When using Celotex insulation boards you need to satisfy yourself that the use of the product meets all relevant national Building Regulations and guidance as well as local, national, and other applicable standards relevant for your construction or application, including requirements concerning fire and applicable height restrictions.


Data Sheets


Important Notice: Please be aware that during periods of high demand, we reserve the right to provide alternative brands that meet the same specifications and quality standards as the products you originally ordered.


Order Value Delivery Charge
Up to £200.00 ex-vat £100.00 ex-vat
£200.00 - £599.95 ex-vat £59.95 ex-vat
Above £599.95 ex-vat Free Delivery


Weekend Delivery
Available upon request


Parcel Rates
Delivery charge may vary depending on quantity and volume of your order.
Pricing will be calculated during checkout.


Local Delivery Charge
Within 35 miles of Postcode S63 9BL - Up to £500.00 ex-vat
Delivery Charge £35.00 ex-vat
Please contact us to arrange collections
Tel: 0300 303 4578 | Email: sales@insulationuk.co.uk


Delivery charges will automatically be calculated within the checkout process.
Orders are only processed for delivery between 8.00am - 5.00pm Monday to Friday excluding bank holidays.
Moffett offload will be used for large bulky deliveries and only when agreed with you.
Please advise of any access issues on ordering.
Delivery is Kerbside only.
In the unlikely event that your delivery is not correct or damaged please notify us immediately and mark any issues on the delivery slip.


    Where We Deliver

    Delivery Areas

    We have a fleet of FORS delivery vehicles all with Moffett mechanical off loads that deliver nationwide. Sometimes we may use 3rd party carriers for smaller orders.


      Product Delivery Times

      The vast majority of our orders are dispatched within 3 working days, this can however be up to 5 working days, please contact us if you require something urgent.
      Speciality items may take up to 5-7 working days.
      We will contact you with in 24/48hrs of your order been placed to confirm delivery times and dates.

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        Customer Reviews

        Based on 56 reviews

        Amazing easy to use

        Richard Clare

        Brilliant installation, excellent quality & Great value
        Many Thanks Richard

        Mr Ian Selley
        Celotex PIR Insulation Board | 2400mm x 1200mm | (All Sizes)

        Really good product and easy to use and cut

        Sean Birdsall
        Celotex PIR Insulation Board | 2400mm x 1200mm | (All Sizes)

        great price and delivery.

        David Masters
        Celotex PIR Insulation Board | 2400mm x 1200mm | (All Sizes)

        Professional, friendly and reliable company.