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90mm Celotex GA4090 PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2
90mm Celotex GA4090 is a polyisocyanurate (PIR) insulation core with composite aluminium foil facings on both sides. Celotex is a multi-purpose insulation board suitable for use in pitched roofs, ceilings, floors and walls.
£40.45£48.54 Ex VATInc VAT£14.05£16.86 Per M2 Add to cart -
90mm Celotex Thermaclass Cavity Wall 21 Insulation Board 1190mm x 450mm Pack of 6 (3.21m2)
90mm Celotex Thermaclass Cavity Wall 21 is a PIR T&G insulation board designed for full-fill cavity wall applications. Low-emissivity foil facing provides versatility during installation, allowing for a 10mm residual cavity.
£122.68£147.22 Ex VATInc VAT£38.22£45.86 Per M2 Add to cart -
90mm Ecotherm Eco-Cavity Full Fill Insulation Board Tongue And Groove 1200mm x 450mm Pack of 4 (2.16m2)
Eco-Cavity Full Fill is suitable for full fill cavity wall applications while maintaining a residual 10 mm cavity. The residual cavity helps resist moisture transfer, aids installation, and accommodates mortar squeeze. The tongue and groove edges to ensure a continuous layer of insulation, increasing protection from wind driven rain and aiding installation.
£58.00£69.60 Ex VATInc VAT£26.85£32.22 Per M2 Add to cart -
90mm Ecotherm Eco-Versal Rigid PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2
90mm Ecotherm Eco-Versal is a polyisocyanurate (PIR) insulation core with composite aluminium foil facings on both sides. Ecotherm Eco-Versal is a multi-purpose insulation board suitable for use in pitched roofs, ceilings, floors and walls.
£40.89£49.07 Ex VATInc VAT£14.20£17.04 Per M2 Add to cart -
90mm Jablite HP+ 70E External Wall Insulation Board 1200mm x 600mm (4′ X 2′) Pack of 6 (4.32m2)
90mm Jablite HP+ 70E External Wall Insulation Board is designed to enhance thermal efficiency for external walls. It can be bonded or mechanically fixed, providing reliable insulation solution.
£49.26£59.11 Ex VATInc VAT£11.40£13.68 Per M2 Add to cart -
90mm Kingspan Kooltherm K103 Insulation Floorboard 2400mm x1200mm Pack of 3 (8.64m2)
90mm Kooltherm K103 is a premium phenolic core floor insulation solution, designed to deliver exceptional performance with solid concrete or suspended timber floors.
£298.12£357.74 Ex VATInc VAT£34.50£41.40 Per M2 Add to cart -
90mm Kingspan Kooltherm K106 Cavity Board Insulation 1200mm x 450mm Pack of 4 (2.16m2)
90mm Kingspan Kooltherm K106 Cavity Board is a premium performance insulation with a fibre-free rigid thermoset phenolic core with a thermal conductivity of just 0.019 W/mK across all thicknesses.
£88.75£106.50 Ex VATInc VAT£41.09£49.31 Per M2 Add to cart -
90mm Kingspan Kooltherm K110 Soffit Board Insulation 2400mm x 1200mm Pack of 3 (8.64m2)
90mm Kingspan Kooltherm K110 Soffit Board Insulation enhances thermal performance in soffit areas with its slim, efficient design. It’s easy to install and improves energy efficiency.
£317.31£380.77 Ex VATInc VAT£36.73£44.08 Per M2 Add to cart -
90mm Kingspan Thermaroof TR26 PIR Insulation Board 2400mm x 1200mm (8′ x 4′) Pack of 3 (8.64m2)
90mm Kingspan TR26 Thermaroof is high-performance insulation that has a fiber-free rigid thermoset polyisocyanurate (PIR) core. Suitable for flat roof application waterproofed with mechanically fixed single-ply waterproofing.
£249.28£299.14 Ex VATInc VAT£28.85£34.62 Per M2 Add to cart -
90mm Recticel Eurothane GP PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2
90mm Recticel Eurothane GP is a polyisocyanurate (PIR) insulation core with composite aluminium foil facings on both sides. Recticel is a multi-purpose insulation board suitable for use in pitched roofs, ceilings, floors and walls.
£38.79£46.55 Ex VATInc VAT£13.47£16.16 Per M2 Add to cart
90mm Insulation Board
90mm insulation board is a thick, rigid insulation panel used to reduce heat transfer through the building fabric. This depth of insulation is specified when space allows, and high levels of thermal resistance are needed to meet modern performance targets.
What is 90mm thick insulation board?
A 90mm thick insulation board is a factory-manufactured panel with a fixed depth of insulation material measuring approximately 90mm from front to back. The core is usually a rigid foam insulation that restricts heat transfer through a closed-cell structure.
The board is rigid and does not compress under normal installation loads. This makes it easier to cut, fit tightly, and maintain consistent performance across the whole wall or floor.
What is 90mm insulation board used for?
An insulation thickness 90mm board is used for:
- Internal masonry walls, including solid wall upgrades.
- Framing walls such as timber or steel stud systems.
- External wall systems behind cladding or render, where the product is approved for the system.
- Floors above unheated spaces, when supported by a suitable structural deck.
- Flat roof build-ups and warm roof systems.
- Pitched roofs, fitted between or over rafters.
- Ceilings beneath concrete or timber floors where insulation is fixed below the structure.
- Full fill cavity walls where the product is approved for that use.
Because 90mm is relatively thick, it is rarely used where space is very tight. It suits projects where thermal performance takes priority over saving internal space. 90mm insulation boards are most common in refurbishments, extensions, and higher-spec new builds.
Types of insulation in 90mm thickness board
90mm insulation boards are available in the following types:
EPS insulation (Expanded Polystyrene)
EPS offers steady thermal performance and has good moisture resistance when correctly detailed. It is often used in floors and external wall systems where cost control matters.
Phenolic insulation Foam Board
Phenolic foam offers high thermal resistance relative to its thickness. It is brittle compared to EPS or PIR, so careful handling is advised. It is commonly preferred to deliver strong performance where increasing insulation thickness is not feasible.
PIR Insulation (Polyisocyanurate)
PIR insulation 90mm board is widely used on internal walls, floors, and ceilings. It offers strong thermal efficiency in both residential and commercial buildings. It is typically installed behind a separate plasterboard lining or structural deck, depending on the application.
Benefits of 90mm thick insulation board
Installing a thick 90mm insulation board has several advantages:
- Strong reduction in heat loss.
- Improved internal comfort.
- Reduced heating demand when correctly specified and installed.
- Stable performance that does not sag or slump.
- Predictable results when calculating U-values.
The rigidity of the board helps limit gaps, improving real-world thermal performance.
Why buy 90mm insulation boards from insulation wholesale?
At Insulation Wholesale, we:
- Stock UK-spec insulation products from established manufacturers.
- Offer clear technical advice from experts who understand site conditions.
- Supply full packs and pallet quantities.
- Keep lead times short so work does not stall.
Our team is set up to support both small refurb jobs and larger trade orders.
FAQ
Where to buy 90mm insulation board?
You can buy insulation 90mm thick board online from Insulation Wholesale. We stock multiple insulation types at this thickness, hold UK stock, and move orders quickly. We also offer trade discounts, pallet deals, and fast nationwide delivery straight to your site.
Best type of 90mm insulation for floor applications?
For floors, 90mm EPS or PIR insulation boards are commonly specified when matched to the required load rating. The board must always be paired with the correct structural deck and vapour control where required.
How effective is 90mm insulation board for loft insulation?
In a loft, a 90mm insulation board performs effectively when insulation is installed between rafters or above a deck. It provides strong thermal resistance in a limited depth and keeps performance consistent.
How to install 90mm rigid insulation on internal walls?
To install a 90mm rigid insulation board internally:
- Check that the wall is dry and reasonably flat.
- Fix the boards using adhesive dabs or mechanical fixings.
- Keep joints tight with no gaps.
- Seal edges to control air movement.
- Finish with plasterboard if the insulation is not pre-bonded.
