Collection: Overlay Boards & Panels

Underfloor Heating Overlay Boards & Low Profile UFH Panels

Explore our comprehensive range of underfloor heating overlay boards, low-profile UFH panels, routed chipboard flooring and castellated underfloor heating panels at ThermRite Shop. Designed for water underfloor heating installations, our systems offer practical solutions for renovations, extensions, new builds and retrofit projects where floor height, heat output and floor finish compatibility are important.

Our range includes ThermRite PRO foil-faced overlay boards, SpiderFix16 and SpiderFix20 pipe fixing panels, HeatBoard routed chipboard flooring, ProTile20 cementitious panels and structural routed cement boards. Whether you are installing underfloor heating over an existing concrete floor, suspended timber floor or a prepared subfloor, we offer solutions for different installation requirements.

Choose from low-profile underfloor heating boards designed to reduce floor build-up, structural UFH panels for joisted floors, and specialist tile-on systems for bathrooms, kitchens and tiled living spaces. Our range caters for professional installers, heating engineers, builders and homeowners throughout the UK.

Which Underfloor Heating Overlay Board Should I Choose?

The best underfloor heating board depends on your existing floor construction, available floor height, heating pipe diameter and intended floor covering. Some systems incorporate pre-routed pipe channels and heat diffusion layers, while others securely hold heating pipe before the application of a suitable levelling compound.

Compare our main underfloor heating overlay systems below to find the right solution for your project.

Note: Panel heights shown do not include additional adhesive, levelling compound, cover boards or finished flooring. Always check the complete floor build-up and product installation requirements before ordering.

Our Underfloor Heating Overlay Board Systems

ThermRite PRO – 16mm & 20mm Low-Profile Overlay Boards

ThermRite PRO underfloor heating overlay boards are designed for water underfloor heating installations where minimal floor build-up and effective heat transfer are priorities.

Manufactured using high-density EPS400 insulation with a factory-bonded 200-micron aluminium foil surface, ThermRite PRO boards provide a strong, insulated pipe retention system with heat diffusion properties.

• 16mm PRO boards: Designed for 12mm pipe at 120mm centres.
• 20mm PRO boards: Designed for 16mm pipe at 150mm centres.
• High-strength EPS400 insulation core.
• 200-micron aluminium foil layer for heat distribution.
• Pre-routed channels for secure pipe installation.
• Suitable for selected tiled, wood, laminate and vinyl floor constructions when installed to the correct specification.
• Suitable for low-profile renovations, extensions and retrofit UFH installations.

ThermRite PRO is particularly suited to projects where an insulated, foil-faced underfloor heating overlay board is preferred over a traditional castellated panel and levelling compound system.

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SpiderFix16 & SpiderFix20 – Low-Profile Pipe Fixing Panels

Our SpiderFix underfloor heating panels offer a straightforward method of securing heating pipe before applying a suitable self-levelling compound.

Manufactured from 100% recycled plastic, SpiderFix panels incorporate self-adhesive backing, interlocking connections and integrated pipe retention profiles. They eliminate the need for individual pipe fixing clips within the panel area and allow flexible pipe spacing configurations.

• SpiderFix16: 16.5mm panel for 12mm underfloor heating pipe.
• SpiderFix20: 20mm panel for 16mm underfloor heating pipe.
• 1200mm x 600mm panels covering 0.72m² each.
• Self-adhesive backing for installation over suitable prepared subfloors.
• Interlocking panel edges for quick and consistent alignment.
• Flexible pipe layouts to suit the heating design.
• Designed for use with compatible flexible fibre-reinforced levelling compounds.

SpiderFix is an excellent option for retrofit underfloor heating installations where low floor build-up, quick pipe installation and accurate spacing are important.

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HeatBoard ONE – Routed Chipboard Underfloor Heating Panels

HeatBoard routed chipboard panels combine a structural floor deck with pre-routed underfloor heating pipe channels, making them ideal for joisted floors, suspended timber floors and new-build floor constructions.

Unlike conventional overlay panels installed above an existing structural floor, HeatBoard can form part of a suitably designed floor decking system, incorporating water underfloor heating directly into the floor structure.

• HeatBoard ONE: 22mm routed chipboard panels measuring 1200mm x 600mm.
• HeatBoard ONE MAX: Larger 2400mm x 600mm routed chipboard panels.
• HeatBoard ULTRA: Grooved chipboard incorporating aluminium heat diffusion plates for enhanced heat transfer.
• Designed for 12mm underfloor heating pipe.
• Dry-fit installation without traditional wet screed.
• Suitable for joisted floors and suspended timber floor constructions.
• Compatible cover boards and fixing accessories available for specified floor finishes.

HeatBoard systems are particularly beneficial for builders and installers looking for an integrated underfloor heating and structural floor decking solution.

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ProTile20 – Direct Tile-On Underfloor Heating Panels

The ThermRite ProTile20 panel is a 20mm cementitious insulation board developed for low-profile water underfloor heating installations beneath tiled floors.

ProTile20 combines thermal insulation with a cementitious surface designed to receive suitable tile finishes directly when installed in accordance with the product specification.

• 20mm cementitious underfloor heating panel.
• Suitable for specified solid floor and retrofit installations.
• Designed for direct tile-on floor constructions.
• Ideal for bathrooms, kitchens and tiled living areas.
• Provides an alternative to systems requiring a separate cement cover board layer.

For tiled floors, selecting a compatible panel, adhesive and installation method is essential to achieve a stable and durable finish.

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Structural & Routed Cement Boards

Our structural and routed cement boards provide solutions for water underfloor heating installations where strength, stability and a cementitious floor construction are required.

The range includes routed boards with pre-formed pipe channels, fibre cement cover boards and installation accessories for compatible underfloor heating systems.

• Routed cementitious boards with integrated pipe channels.
• Selected systems designed for 12mm pipe at 150mm centres.
• Suitable for specified dry screed and tiled floor constructions.
• 6mm fibre cement cover boards available for compatible HeatBoard installations.
• Durable overlay solutions for renovation and new-build applications.

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Key Benefits of Underfloor Heating Overlay Boards

Low Floor Build-Up for Renovations

Low-profile underfloor heating boards are particularly suitable for retrofit projects where raising the existing floor level could affect door thresholds, skirting boards or ceiling heights. Selected systems start from just 16mm in panel height, although additional installation materials and finished flooring must also be considered.

Efficient Heat Distribution

Foil-faced routed boards, aluminium diffusion plates and compatible levelling compounds help transfer heat from the water pipe into the floor covering. The overall heating performance depends on pipe spacing, water temperature, floor construction, insulation and the final floor finish.

Fast and Straightforward Installation

Pre-routed pipe channels and castellated pipe retention panels help simplify installation by maintaining correct pipe positions and spacing. Systems such as SpiderFix include self-adhesive backing, while HeatBoard uses routed structural flooring to integrate the pipework directly into the floor deck.

Solutions for Different Floor Finishes

Our range includes systems for tiled floors, engineered wood, laminate and selected vinyl floor constructions. Always verify the required adhesive, levelling compound, cover board or other preparation for your chosen floor finish.

Suitable for Timber and Concrete Floors

Different UFH overlay systems accommodate different subfloor constructions. ThermRite PRO and SpiderFix panels are suitable for selected retrofit applications, while HeatBoard provides a dedicated solution for joisted timber floors. Cementitious boards offer further options for robust floor build-ups.

Which Underfloor Heating Board Is Best for My Floor Type?

Different floor structures require different underfloor heating solutions. Choosing the right panel is essential for achieving the required heat output while maintaining a stable finished floor.

All recommendations are subject to the relevant floor construction, manufacturer installation instructions and underfloor heating design.

Low-Profile Underfloor Heating vs Traditional Screeded Systems

Traditional water underfloor heating is commonly installed within a substantial screed layer over insulation. Although effective for new-build floors, this approach can be impractical for some existing properties due to the required installation depth and additional floor weight.

Low-profile underfloor heating overlay systems offer an alternative by positioning the heating pipe within slim routed panels or castellated pipe retention boards above a suitable existing subfloor.

Key advantages may include:

• Reduced floor build-up compared with many traditional screeded systems.
• Less disruption during suitable renovation projects.
• Pre-formed pipe channels or retention profiles for accurate installation.
• Options for dry-fit flooring systems without conventional wet screed.
• Compatibility with a variety of finished floor constructions.
• Suitable designs for modern low-temperature heating systems.

The correct system should always be chosen according to the room's heat loss, available floor height, structural requirements and heating design.

Underfloor Heating Overlay Boards for Heat Pumps

Water underfloor heating is frequently used alongside air source and ground source heat pumps because it can deliver comfortable room temperatures using relatively low heating water temperatures.

Correctly designed overlay board systems, including ThermRite PRO, SpiderFix and selected HeatBoard systems, can be incorporated into heat pump underfloor heating installations.

Heat output depends on several factors, including the pipe spacing, flow temperature, floor covering, insulation and room heat loss. Systems should be designed to meet the heating demand rather than selecting a panel based on its thickness alone.

Frequently Asked Questions About Underfloor Heating Overlay Boards

What are underfloor heating overlay boards?

Underfloor heating overlay boards are panels designed to accommodate water underfloor heating pipe above or within a prepared floor construction. They often feature routed grooves, foil heat diffusion layers or castellated pipe fixing profiles. Overlay boards are commonly used in retrofit and renovation projects where a low-profile heating system is required.

What is the thinnest underfloor heating overlay board?

ThermRite PRO 16mm is one of the lowest-profile routed board options in our range, designed for 12mm pipe. SpiderFix16 has a 16.5mm panel height and also accommodates 12mm pipe. Additional materials and the finished floor covering will increase the total floor build-up.

What is the difference between ThermRite PRO and SpiderFix panels?

ThermRite PRO is a foil-faced EPS400 routed overlay board with pre-formed pipe channels and insulation properties. SpiderFix is a plastic castellated pipe retention panel designed to hold pipe before encapsulation in a suitable self-levelling compound. The preferred system depends on the floor construction, heating requirements and floor finish.

Can I install underfloor heating over an existing concrete floor?

Yes. Many low-profile underfloor heating systems can be installed over an existing concrete subfloor, provided it is structurally sound, level, dry and properly prepared. ThermRite PRO and SpiderFix are suitable options for appropriately designed retrofit installations.

What underfloor heating boards are best for timber floors?

HeatBoard ONE, ONE MAX and ULTRA are designed for suitable joisted and suspended timber floor installations. They combine routed chipboard flooring with pre-formed water underfloor heating pipe channels, helping integrate the heating system into the floor deck.

Can I tile directly onto underfloor heating overlay boards?

Some systems, including ProTile20, are specifically designed for direct tile-on installations using the required adhesive and preparation. Other systems may need levelling compound or a suitable cover board. Always follow the installation specification for the selected panel and tile finish.

Do overlay boards need self-levelling compound?

Not all overlay boards require self-levelling compound. SpiderFix systems are designed to be encapsulated using a compatible levelling compound, while selected foil-faced routed and dry-fit board systems use different floor build-ups. Check the installation requirements before selecting a system.

Are overlay boards suitable for heat pumps?

Yes. Appropriately designed water underfloor heating overlay systems can work with air source and ground source heat pumps. The heating design must account for the flow temperature, pipe spacing, floor construction, floor covering and required room heat output.

Can underfloor heating overlay boards be used beneath laminate or wood flooring?

Yes. Selected systems, including ThermRite PRO and compatible HeatBoard constructions, can be used beneath suitable wood and laminate floor finishes. The floor manufacturer's thermal resistance and temperature limitations must be followed.

What pipe sizes are used with underfloor heating overlay boards?

Our range includes systems for both 12mm and 16mm underfloor heating pipe. ThermRite PRO 16mm and SpiderFix16 use 12mm pipe, while ThermRite PRO 20mm and SpiderFix20 use 16mm pipe. HeatBoard ONE systems are designed for 12mm pipe. Always select pipe compatible with the specified panel.

Do underfloor heating overlay boards provide insulation?

Some panels, such as ThermRite PRO, incorporate an EPS insulation core. Other products, including SpiderFix pipe fixing panels, primarily provide pipe retention and may need additional thermal insulation beneath the system. The required insulation depends on the existing floor and applicable building requirements.

Shop Underfloor Heating Boards, Panels & Accessories

At ThermRite Shop, we supply underfloor heating boards and accessories for professional installers, contractors and homeowners. Explore our specialist collections to find a suitable system for your floor construction.

• ThermRite PRO Overlay Boards – Foil-faced low-profile 16mm and 20mm routed UFH panels.
• SpiderFix & Castellated Panels – Self-adhesive low-profile pipe retention panels for 12mm and 16mm pipe.
• HeatBoard Routed Chipboard Panels – Structural chipboard flooring with integrated UFH pipe channels.
• Solid Floor Tile-On Panels – Cementitious systems for compatible tiled floor installations.
• Structural & Routed Cement Boards – Routed cement boards and specialist cover boards for UFH installations.
• Water Underfloor Heating Systems – Browse underfloor heating components and complete installation solutions.

Need help selecting the right underfloor heating board? Our team can help you compare overlay systems based on your existing floor, available installation height, pipe diameter, heat output requirements and intended floor finish.