20mm Celotex TB4020 PIR Insulation Board 2400mm x 1200mm

URN: 3001023
£13.00ex. VAT £4.51 per m2
£13.00ex. VAT
£4.51 per m2
Coverage required
m
m
Based on your total area of m2 (inc. 10% wastage) - of these are required (actual coverage of m2)

We recommend purchasing at least 10% extra product to allow for errors, damages or obstacles

PIR insulation board with foil facings, designed to combat thermal bridging. Suitable for floors, walls, and roofs. Ultra-slim 20mm profile ideal for over-boarding and use where space is very limited.

Nationwide Delivery

Fri 19 Sep

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Product Overview

PIR insulation board with foil facings, designed to combat thermal bridging. Suitable for floors, walls, and roofs. Ultra-slim 20mm profile ideal for over-boarding and use where space is very limited.

URN: 3001023
£13.00ex. VAT

Delivery & Returns Information

How Our Delivery Works

We work with a nationwide network of trusted suppliers. As a result, items in your basket may be supplied by different suppliers and delivered separately. Where this applies, you'll see multiple delivery charges at checkout. We always aim to group products from the same supplier to keep delivery costs as low as possible.

Delivery Areas & Charges

Delivery charges listed on our website apply to mainland UK, excluding the following postcode areas: AB, CF, DD, DG, FK, KW, IV, LA, LD, LL, NP, PA, PH, SA, SY
If your delivery address falls within one of these postcode areas, we’ll be in touch before processing your order to confirm any additional delivery costs.
Please note: We do not currently offer delivery outside the UK mainland.

Standard (Nationwide) Delivery

Insulation, Plasterboard and Drylining Products
ORDER VALUE DELIVERY CHARGE
Under £350 £35 ex. VAT
Over £350 ex. VAT FREE
Timber & Sheet, Building Materials, Joinery and Gardens & Landscaping Products
ORDER VALUE DELIVERY CHARGE
Under £100 £15 ex. VAT
Between £100 - £300 ex. VAT £10 ex. VAT
Over £300 ex. VAT FREE
Screws & Fixings and Adhesives & Sealants
ORDER VALUE DELIVERY CHARGE
Under £50 £5 ex. VAT
Over £50 ex. VAT FREE

Express Delivery

Express Delivery - Insulation and Plasterboard & Drylining
ORDER VALUE DELIVERY CHARGE
Under £400 £50 ex. VAT
Over £400 ex. VAT £35 ex. VAT
Express Delivery - Timber & Sheet, Building Materials, Joinery and Gardens & Landscaping Products
ORDER VALUE DELIVERY CHARGE
Under £300 £50 ex. VAT
Over £300 ex. VAT £35 ex. VAT

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Returns

We offer a 30 day returns policy on any faulty products.

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Key Features

  • {{home}} Use in floors, framed walls and pitched roofs
  • {{grade}} Aluminium composite facing on both sides
  • {{thermostat}} 0.022 W/mK thermal conductivity
  • {{build}} Easy to handle and install
  • {{public}} Zero Ozone Depletion Potential (ODP)
  • {{verified_user}} BBA certified

Technical Specification

Technical Specification
Material Type:PIR
Thickness:20mm
Width:1200mm
Length:2400mm
Sales Unit:Board
Sales Unit Coverage:2.88m2
Brand:Celotex
Manufacturer's Reference:TB4020
Weight:2.28kg
Thermal Conductivity:0.022W/mK

Product Overview

Foil-faced PIR insulation board for use in floors, walls, and roofs. 

Part of the TB4000 range, it is used to limit thermal bridging at reveals, junctions, and edges where insulation layers are interrupted. 

At 20mm thick, this is the slimmest option in the range, suited to over-boarding, detail work, and space-constrained applications.

Features & Benefits

  • Thermal conductivity (0.022 W/m·K): Reduces the thickness required to meet U-value targets.
  • Low-emissivity foil facings: Reflect radiant heat across unventilated air gaps, cutting thermal transfer at junctions.
  • TB4000 range (thermal bridging control): Improves continuity of insulation where up to 30% of fabric heat loss can otherwise occur.
  • Rigid PIR core: Lightweight yet robust, easy to cut and install with standard tools.
  • Moisture resistance: Closed-cell core prevents water uptake and preserves thermal performance.
  • Environmental credentials: Zero ODP, low GWP blowing agent, and BRE Green Guide Rating A.
  • BBA certified (17/5405, 16/5352): Independent assurance of performance across roofs, walls, and floors.
  • Board size 2400 x 1200mm: Large-format sheets reduce installation time.
  • Thickness 20mm: Slimmest PIR option, enabling insulation where space is most limited.

Applications

  • Thermal bridging details (reveals, lintels, junctions): Limits cold spots, condensation risk, and heat loss where insulation layers are interrupted.
  • Roofs (pitched/flat): Useful for upgrades at rafter lines, perimeter upstands, or overlaying to reduce bridging.
  • Walls (timber frame/masonry): Applied at reveals, edges, or internally to improve continuity.
  • Floors (beam & block, slab, timber): Commonly used as perimeter upstand insulation or for targeted slab upgrades.


Installation Guidance

  • Cut and fit tightly: Use a knife or fine-tooth saw; maintain close joints to avoid thermal bypass.
  • Seal or tape as specified: Ensures continuity with air and vapour control layers.
  • Protect on site: Store boards flat, dry, and covered until required.

Compliance & Performance

  • Thermal conductivity: 0.022 W/m·K (BS EN 12667).
  • Compressive strength: ≥140 kPa (BS EN 826).
  • Reaction to fire: Euroclass E (BS EN 13501-1).
  • Environmental performance: Zero ODP, low GWP, BRE Green Guide Rating A.



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