Floor Insulation
Celotex offers PIR and XPS floor insulation products for concrete floors, beam and block floors and suspended timber floors.
U-value Calculator
Start your U-value calculationFloor insulation and thermal performance
With the correct specification, installation and detailing, floor insulation can enhance thermal performance, support compliance with Part L (Conservation of Fuel and Power) and contribute to thermal comfort for building occupants.
The Celotex collection of rigid insulation boards includes products suitable for use as floor insulation in new-build and refurbishment projects. They are manufactured to provide:
- Thermal conductivity: With lambda values as low as 0.022 W/m⋅K, Celotex floor insulation can support compliance with U-value targets when correctly specified and installed.
- Compressive strength: Products are available in a range of compressive strengths, up to 700 kPa, providing stability for various loading conditions.
- Moisture resistance: The XPS closed-cell structure absorbs very little water, less than 0.7% by volume (tested to EN 12087), helping to protect thermal performance over time.
PIR or XPS: Choosing floor insulation for a project
Celotex offers two types of floor insulation:
- PIR floor insulation: Polyisocyanurate (PIR) insulation offers low thermal conductivity, with lambda values of 0.022 W/m⋅K. It is suitable for installation under concrete slabs or within suspended timber floors and beam and block floors. Products are available in a range of thicknesses to meet various design needs.
- XPS floor insulation: Extruded polystyrene (XPS) insulation is available with compressive strengths of 300, 500 or 700 kPa to suit a range of loading requirements, including commercial ground floors beneath the concrete slab.
Which type of floor insulation for your project?
Celotex PIR and XPS floor insulation products are available to suit a range of applications, from residential retrofits to new-build commercial developments. They can be used across various types of floor constructions, including:
- Concrete floor insulation
- Beam and block floor insulation
- Suspended timber floor insulation
Depending on the product, Celotex floor insulation can be provided in thicknesses of 20 to 280mm, supporting buildings in meeting designed thermal performance targets and building regulations.
Insulating floors in both retrofit and new-build projects
Celotex floor insulation is suitable for new-build projects, supporting Part L compliance when correctly specified and installed and meeting the designed U-values for the thermal envelope.
In refurbishment projects, boards can be used to upgrade existing floors, helping to achieve current thermal performance requirements.
The Celotex online U-value calculator can help specifiers identify the right floor insulation product and thickness for a project. Also refer to product data sheets, relevant BBA certificates and declarations of performance.
Celotex floor insulation products
The Celotex range of floor insulation products includes:
- Celotex PIR Series (GA4000, XR4000, TB4000) – Rigid PIR insulation boards suitable for suspended floor insulation and solid floors.
- Celotex XPS Series (300 SL FN, 500 SL FS, 700 SL FS) – Extruded polystyrene insulation for applications where high compressive strength is required.
| Material | ||||
| PIR | XPS | Thickness range (mm) | Lambda value (W/m⋅K) | |
| TB4000 | X | 20-40 | 0.022 | |
| GA4000 | X | 50-100 | ||
| XR4000 | X | 110-200 | ||
| XPS 300 SL FN | X | 40-280 | 0.032-0.033 | |
| XPS 500 SL FS | X | 60-280 | 0.033-0.035 | |
| XPS 700 SL FS | X | 60-280 | 0.033-0.035 | |
For more information about Celotex floor insulation products or to discuss your project, please contact us. You can also use our online U-value calculator to help determine the right product for your requirements.
