Unilin Thin-R XT/PR_UF Underfloor Insulation Boards are high-performance PIR insulation boards designed specifically for insulating ground supported and suspended floors.
The floor in any building is an area of significant downward heat loss when not properly insulated.
Thin-R XT/PR_UF significantly improves the U-value of both new and existing floors, helping reduce energy loss and improve overall thermal efficiency.
Thin-R XT/PR_UF is lightweight, easy to install and combines high compressive strength with low thermal conductivity, providing a high-performance solution for floor insulation in both domestic and commercial applications.
Manufactured with a rigid PIR core and composite low emissivity foil facings, these boards deliver excellent thermal performance while maintaining a slim profile—ideal where floor build-up height is limited.
Features:
- High-performance PIR floor insulation
- Suitable for ground supported and suspended floors
- Suitable for new build and refurbishment applications
- Suitable for use in underfloor heating systems (subject to system design)
- High compressive strength (CS(10/Y) 140 kPa)
- Lightweight and easy to install
- Reduced thermal bridging
- Reduced risk of condensation
- Closed-cell PIR structure for high moisture resistance
- Composite low emissivity foil facings
- Excellent thermal performance with reduced insulation thickness
- Board size: 2400mm x 1200mm (8ft x 4ft)
- Coverage per board: 2.88m²
- Available thicknesses: 20mm, 25mm, 40mm, 50mm, 60mm, 75mm, 100mm, 125mm and 150mm
Technical Information:
- Range: Thin-R XT/PR_UF
- Material: PIR (Polyisocyanurate)
- Thermal Conductivity: 0.022 W/mK (tested to BS EN 13165)
- Compressive Strength: 140 kPa (CS(10/Y))
- Reaction to Fire: Euroclass F
- Facing: Composite foil facings both sides
- Board Dimensions: 2400mm x 1200mm
- Coverage: 2.88m² per sheet
- Standard: Manufactured in accordance with BS EN 13165
- Environmental: Environmental Product Declaration (EPD) available on request
Documentation:
Thermal Resistance (R-Values):
- 20mm – 0.90 m²K/W
- 25mm – 1.10 m²K/W
- 40mm – 1.80 m²K/W
- 50mm – 2.25 m²K/W
- 60mm – 2.73 m²K/W
- 75mm – 3.41 m²K/W
- 100mm – 4.50 m²K/W
- 125mm – 5.65 m²K/W
- 150mm – 6.80 m²K/W
Applications:
- Ground supported concrete floors
- Suspended timber floors
- Beam and block floor systems
- New build projects
- Renovation and retrofit applications
- Domestic and commercial floor construction applications
Benefits of Insulation Boards:
Enhanced Energy Efficiency: Helps reduce heat loss through floors, improving thermal performance and reducing energy demand.
Moisture Resistance: Closed-cell PIR core resists moisture ingress, helping reduce condensation risk and improve long-term performance.
Space Saving: High thermal efficiency allows thinner insulation solutions while achieving strong U-value performance.
Improved Comfort: Helps create warmer floor surfaces and a more consistent internal environment.
Installation Guide:
- Ensure the floor surface is clean, dry, and level before installation.
- Measure and cut boards accurately using a fine-toothed saw or sharp knife.
- Install boards tightly together to minimise gaps and thermal bridging.
- Seal joints where required in line with project specifications.
- Install screed or floor finishes as per system design requirements.
With rising energy costs and increasing focus on building efficiency, Unilin Thin-R XT/PR_UF floor insulation boards provide a reliable, high-performance solution for reducing heat loss through floors while improving comfort and long-term energy savings.