Floor Insulation

Types of Floor Insulation

PIR Floor Insulation Boards

PIR (polyisocyanurate) boards offer high thermal performance, with conductivity as low as 0.022 W/mK. This makes them ideal where space is limited but strong insulation performance is required.

Commonly used in both concrete floors and suspended timber floors, PIR boards are lightweight, easy to cut and install, and widely used in new builds and refurbishments. Popular options include Celotex GA4000, Kingspan TF70 and Recticel Eurothane GP.

EPS Floor Insulation

EPS (expanded polystyrene) provides a cost-effective solution for insulating solid floors. Available in a range of compressive strengths, EPS insulation is suitable for domestic, commercial and industrial applications.

Lower grades such as EPS70–100 are typically used in domestic floors, while higher grades like EPS200–500 are suited to heavier load-bearing areas.

XPS Insulation Boards

XPS (extruded polystyrene) boards are designed for high moisture resistance and compressive strength, making them ideal for basements, below-ground applications and areas exposed to damp conditions.

With excellent long-term durability, XPS insulation is often used where both strength and moisture resistance are important.

Mineral Wool for Suspended Floors

Mineral wool insulation is commonly used in suspended timber floors, fitting between joists to provide both thermal and acoustic insulation.

Products such as Rockwool RWA45 and Knauf Acoustic Roll offer flexible installation, helping to reduce heat loss while improving sound insulation between floors.

Benefits of Floor Insulation

• Reduce heat loss and improve energy efficiency
• Lower heating bills over time
• Improve comfort with warmer floor surfaces
• Help achieve Building Regulations compliance
• Suitable for a wide range of floor types and applications
• Options available for moisture-prone or high-load environments
• Reduce sound transmission when using acoustic materials
• Long-lasting performance with minimal maintenance

Floor Insulation by Application

Choosing the right floor insulation depends on your floor type and how you use the space. 

Concrete Floor Insulation

Solid concrete floors require insulation that can withstand load while delivering strong thermal performance. PIR boards, EPS insulation and XPS boards are commonly used depending on compressive strength and moisture exposure.

Suspended Timber Floor Insulation

Suspended floors are typically insulated between joists using mineral wool or rigid boards cut to size. Flexible mineral wool is particularly effective at fitting tightly between joists, helping to reduce draughts and improve both thermal and acoustic performance.

Underfloor Heating Insulation

Insulation is essential for underfloor heating systems, helping to reduce heat loss and improve efficiency. High-performance boards beneath heating systems allow faster heat-up times and improved energy use.

Acoustic Floor Insulation

To reduce noise transfer between floors, high-density mineral wool or specialist acoustic systems can be used alongside structural insulation layers.

Choosing the Right Floor Insulation

The best type of floor insulation depends on your floor structure, available space and performance requirements.

For solid concrete floors, rigid insulation boards such as PIR, EPS  and XPS provide the compressive strength and thermal performance needed to support loads.

For suspended timber floors, mineral wool insulation is often preferred due to its flexibility and ease of installation between joists.

Where floor build-up height is limited, PIR insulation boards offer high thermal performance in thinner profiles. In damp or below-ground environments, XPS insulation provides added moisture resistance and durability.

If you're unsure which insulation is right for your project, you can use the filters above or contact our team for guidance.

Floor Insulation Accessories 

A complete floor insulation system is often more than just the insulation boards. Fixings, tapes and edging solutions can help improve performance and ensure a professional finish.

Foil tapes can help reduce air leakage, perimeter edging strips allow for expansion in screeded floors, and appropriate adhesives and fixings ensure boards are securely installed.

Getting these details right can make a significant difference to the overall performance of your insulation system.

Why Choose Insulation UK for Floor Insulation?

All floor insulation types in one place
From PIR and EPS to XPS and mineral wool, we stock solutions for every floor type and application.

Trusted industry brands
Shop leading manufacturers including Celotex, Kingspan, Recticel, Jablite, Rockwool and Knauf.

Competitive trade prices
We offer high-performance floor insulation at competitive prices, with no minimum order value.

Fast UK-wide delivery
Reliable nationwide delivery, with free shipping available on some products.

Expert support when you need it
With over 50 years of industry experience, our team can help you choose the right insulation for your project.

Browse our full range of floor insulation products above and filter by thickness, material or application to find the right solution. If you need help choosing, get in touch with our team or call us on 03003 034 578.