100mm Celotex GA4100 PIR Insulation Board 2.4m x 1.2m - 2.88m2 per sheet
As the thickest board in the general-purpose GA4000 range, 100mm Celotex GA4100 is the most widely specified Celotex polyisocyanurate (PIR) thickness and a default choice across floors, walls and roofs. The round-number 100mm depth carries the highest single-board thermal resistance in the range, which is why it is so often the board reached for first on solid floors, underfloor heating and standard build-ups.
Each board measures 2400mm x 1200mm, covers 2.88m² and is sold individually. With a declared thermal conductivity of 0.022 W/mK and a thermal resistance of 4.50 m²K/W, 100mm GA4100 delivers the strongest single-layer figure in the GA4000 range, at around 4.15 kg per square metre. The rigid PIR core is faced both sides with a low-emissivity aluminium foil that lifts performance against a sealed cavity air space, and the square edges butt together for a continuous, tight-jointed layer.
On solid ground floors, 100mm GA4100 is typically laid over the damp-proof membrane beneath the screed, where it commonly meets the Part L floor target, and it suits underfloor heating, beam-and-block, oversite and suspended timber floors equally well. The same board is used as a single layer in pitched roofs between or under rafters, in timber-frame walls and internal dry lining, and in flat-roof build-ups within the GA4000 range's scope. Install it in line with the latest Celotex technical guidance, the project specification and current Building Regulations, including fire requirements and the height limit on external wall use. For new build and refurbishment alike, the 100mm board offers the range's strongest single-layer resistance in the standard GA4000 format and handling.
Key Benefits of 100mm Celotex GA4100:
- 100mm rigid polyisocyanurate (PIR) board, the range-topping and most widely specified thickness in the general-purpose GA4000 range, for floors, walls and roofs.
- Thermal resistance (R-value) of 4.50 m²K/W, the highest single-board figure in the GA4000 range.
- Declared thermal conductivity of 0.022 W/mK, delivering that resistance in a slim 100mm build-up.
- The default choice for solid ground floors beneath screed and for underfloor heating, where the round 100mm depth commonly meets the Part L floor target.
- Works as a strong single layer in pitched roofs, timber-frame walls and internal dry lining, and in flat-roof build-ups within the GA4000 scope.
- Low-emissivity aluminium foil facings on both sides, improving performance against sealed and cavity air spaces.
- Square edges for flush, tight joints and a continuous insulation layer.
- Manufactured with a blowing agent of zero Ozone Depletion Potential (ODP) and low Global Warming Potential (GWP), free of CFCs and HCFCs.
- Supplied as a single 2400mm x 1200mm board covering 2.88m², at around 4.15 kg per square metre.
- BBA certified (Certificate 25/7318) for defined pitched roof, dry lining and floor applications.
Good to know:
- Boards measure 2400mm x 1200mm and are sold individually, each covering 2.88m².
- The foil facing is printed on one side only: fit the board with the plain face towards the cavity for the rated thermal performance.
- On a solid floor, lay the boards over the damp-proof membrane beneath the screed, with joints staggered and taped with aluminium foil tape.
- The foil facing is not a vapour control layer; many build-ups still need a separate VCL to manage interstitial condensation.
- In wall applications the board should be covered with a fire-rated lining, such as 12.5mm plasterboard.
- Celotex GA4000 should not be used in the external walls of buildings over 11 metres in height; check current Building Regulations for your project.
- PIR is moisture resistant but not waterproof: store boards flat, off the ground, dry and out of prolonged sunlight.
- Insulation UK offers a bespoke cutting service, supplying boards cut to your sizes to reduce waste and on-site mess.
As the range-topping GA4000 board, 100mm Celotex GA4100 brings the strongest single-layer thermal resistance in the general-purpose range to floors, walls and roofs, keeping specification simple while supporting lower U-values and lasting energy efficiency.
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.
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100mm Celotex GA4100 PIR Insulation Board 2.4m x 1.2m - 2.88m2 per sheet
100mm Celotex GA4100 PIR Insulation Board 2.4m x 1.2m - 2.88m2 per sheet
As the thickest board in the general-purpose GA4000 range, 100mm Celotex GA4100 is the most widely specified Celotex polyisocyanurate (PIR) thickness and a default choice across floors, walls and roofs. The round-number 100mm depth carries the highest single-board thermal resistance in the range, which is why it is so often the board reached for first on solid floors, underfloor heating and standard build-ups.
Each board measures 2400mm x 1200mm, covers 2.88m² and is sold individually. With a declared thermal conductivity of 0.022 W/mK and a thermal resistance of 4.50 m²K/W, 100mm GA4100 delivers the strongest single-layer figure in the GA4000 range, at around 4.15 kg per square metre. The rigid PIR core is faced both sides with a low-emissivity aluminium foil that lifts performance against a sealed cavity air space, and the square edges butt together for a continuous, tight-jointed layer.
On solid ground floors, 100mm GA4100 is typically laid over the damp-proof membrane beneath the screed, where it commonly meets the Part L floor target, and it suits underfloor heating, beam-and-block, oversite and suspended timber floors equally well. The same board is used as a single layer in pitched roofs between or under rafters, in timber-frame walls and internal dry lining, and in flat-roof build-ups within the GA4000 range's scope. Install it in line with the latest Celotex technical guidance, the project specification and current Building Regulations, including fire requirements and the height limit on external wall use. For new build and refurbishment alike, the 100mm board offers the range's strongest single-layer resistance in the standard GA4000 format and handling.
Key Benefits of 100mm Celotex GA4100:
- 100mm rigid polyisocyanurate (PIR) board, the range-topping and most widely specified thickness in the general-purpose GA4000 range, for floors, walls and roofs.
- Thermal resistance (R-value) of 4.50 m²K/W, the highest single-board figure in the GA4000 range.
- Declared thermal conductivity of 0.022 W/mK, delivering that resistance in a slim 100mm build-up.
- The default choice for solid ground floors beneath screed and for underfloor heating, where the round 100mm depth commonly meets the Part L floor target.
- Works as a strong single layer in pitched roofs, timber-frame walls and internal dry lining, and in flat-roof build-ups within the GA4000 scope.
- Low-emissivity aluminium foil facings on both sides, improving performance against sealed and cavity air spaces.
- Square edges for flush, tight joints and a continuous insulation layer.
- Manufactured with a blowing agent of zero Ozone Depletion Potential (ODP) and low Global Warming Potential (GWP), free of CFCs and HCFCs.
- Supplied as a single 2400mm x 1200mm board covering 2.88m², at around 4.15 kg per square metre.
- BBA certified (Certificate 25/7318) for defined pitched roof, dry lining and floor applications.
Good to know:
- Boards measure 2400mm x 1200mm and are sold individually, each covering 2.88m².
- The foil facing is printed on one side only: fit the board with the plain face towards the cavity for the rated thermal performance.
- On a solid floor, lay the boards over the damp-proof membrane beneath the screed, with joints staggered and taped with aluminium foil tape.
- The foil facing is not a vapour control layer; many build-ups still need a separate VCL to manage interstitial condensation.
- In wall applications the board should be covered with a fire-rated lining, such as 12.5mm plasterboard.
- Celotex GA4000 should not be used in the external walls of buildings over 11 metres in height; check current Building Regulations for your project.
- PIR is moisture resistant but not waterproof: store boards flat, off the ground, dry and out of prolonged sunlight.
- Insulation UK offers a bespoke cutting service, supplying boards cut to your sizes to reduce waste and on-site mess.
As the range-topping GA4000 board, 100mm Celotex GA4100 brings the strongest single-layer thermal resistance in the general-purpose range to floors, walls and roofs, keeping specification simple while supporting lower U-values and lasting energy efficiency.
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.
Product Information
Product Information
Shipping & Returns
Shipping & Returns
Description
As the thickest board in the general-purpose GA4000 range, 100mm Celotex GA4100 is the most widely specified Celotex polyisocyanurate (PIR) thickness and a default choice across floors, walls and roofs. The round-number 100mm depth carries the highest single-board thermal resistance in the range, which is why it is so often the board reached for first on solid floors, underfloor heating and standard build-ups.
Each board measures 2400mm x 1200mm, covers 2.88m² and is sold individually. With a declared thermal conductivity of 0.022 W/mK and a thermal resistance of 4.50 m²K/W, 100mm GA4100 delivers the strongest single-layer figure in the GA4000 range, at around 4.15 kg per square metre. The rigid PIR core is faced both sides with a low-emissivity aluminium foil that lifts performance against a sealed cavity air space, and the square edges butt together for a continuous, tight-jointed layer.
On solid ground floors, 100mm GA4100 is typically laid over the damp-proof membrane beneath the screed, where it commonly meets the Part L floor target, and it suits underfloor heating, beam-and-block, oversite and suspended timber floors equally well. The same board is used as a single layer in pitched roofs between or under rafters, in timber-frame walls and internal dry lining, and in flat-roof build-ups within the GA4000 range's scope. Install it in line with the latest Celotex technical guidance, the project specification and current Building Regulations, including fire requirements and the height limit on external wall use. For new build and refurbishment alike, the 100mm board offers the range's strongest single-layer resistance in the standard GA4000 format and handling.
Key Benefits of 100mm Celotex GA4100:
- 100mm rigid polyisocyanurate (PIR) board, the range-topping and most widely specified thickness in the general-purpose GA4000 range, for floors, walls and roofs.
- Thermal resistance (R-value) of 4.50 m²K/W, the highest single-board figure in the GA4000 range.
- Declared thermal conductivity of 0.022 W/mK, delivering that resistance in a slim 100mm build-up.
- The default choice for solid ground floors beneath screed and for underfloor heating, where the round 100mm depth commonly meets the Part L floor target.
- Works as a strong single layer in pitched roofs, timber-frame walls and internal dry lining, and in flat-roof build-ups within the GA4000 scope.
- Low-emissivity aluminium foil facings on both sides, improving performance against sealed and cavity air spaces.
- Square edges for flush, tight joints and a continuous insulation layer.
- Manufactured with a blowing agent of zero Ozone Depletion Potential (ODP) and low Global Warming Potential (GWP), free of CFCs and HCFCs.
- Supplied as a single 2400mm x 1200mm board covering 2.88m², at around 4.15 kg per square metre.
- BBA certified (Certificate 25/7318) for defined pitched roof, dry lining and floor applications.
Good to know:
- Boards measure 2400mm x 1200mm and are sold individually, each covering 2.88m².
- The foil facing is printed on one side only: fit the board with the plain face towards the cavity for the rated thermal performance.
- On a solid floor, lay the boards over the damp-proof membrane beneath the screed, with joints staggered and taped with aluminium foil tape.
- The foil facing is not a vapour control layer; many build-ups still need a separate VCL to manage interstitial condensation.
- In wall applications the board should be covered with a fire-rated lining, such as 12.5mm plasterboard.
- Celotex GA4000 should not be used in the external walls of buildings over 11 metres in height; check current Building Regulations for your project.
- PIR is moisture resistant but not waterproof: store boards flat, off the ground, dry and out of prolonged sunlight.
- Insulation UK offers a bespoke cutting service, supplying boards cut to your sizes to reduce waste and on-site mess.
As the range-topping GA4000 board, 100mm Celotex GA4100 brings the strongest single-layer thermal resistance in the general-purpose range to floors, walls and roofs, keeping specification simple while supporting lower U-values and lasting energy efficiency.
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.
