Choosing the Right Reflective Film for Underfloor Heating

Reflective film is a cost-effective way to improve underfloor heating performance, and understanding how to choose and install it helps homeowners get the most from their heating system. This guide explains what to look for when selecting reflective film.

What to Look for in Reflective Film

Not all reflective film is the same. The best films have a high reflectivity rating, typically above 95 percent, which means they bounce most of the radiant heat back into the room. Look for films with a durable polyethylene or polyester backing that resists tearing during installation. The film should also be wide enough to minimize joints, as each joint is a potential point of heat loss.

Key Features to Consider

• Reflectivity rating: Choose a film with 95 percent or higher reflectivity.

• Backing material: Durable polyethylene or polyester backing that resists tearing.

• Width: Wider rolls minimize joints and reduce installation time.

• Vapor barrier: Some films include a built-in moisture barrier, ideal for ground floors.

• Compatibility: Ensure the film works with your chosen insulation and pipe system.

Installation Best Practices

Lay the film across a clean, level subfloor with the reflective side facing up. Overlap joints by at least 10 centimeters and seal them with aluminum foil tape. Pay special attention to edges and corners, where gaps can reduce the film's effectiveness. Once the film is sealed, pipes or insulation boards can be installed on top as normal.

Where to Use Reflective Film

Reflective film is suitable for all types of underfloor heating systems, including both new builds and renovations. It is particularly beneficial over unheated spaces, such as garages or crawl spaces, where heat loss is greatest. It can also be used in conjunction with rigid insulation boards to create a complete thermal barrier.

Conclusion

Choosing the right reflective film is a matter of considering reflectivity, durability, width, and compatibility. By selecting a quality film and installing it correctly, homeowners can enjoy a more efficient and comfortable underfloor heating system.

References

[1] Underfloor Heating Systems: Design, Installation and Performance. Journal of Building Engineering, Elsevier.
[2] Thermal Analysis of Radiant Floor Heating Systems. Energy and Buildings, Elsevier.
[3] Materials and Components for Underfloor Heating. Construction and Building Materials, Elsevier.