Choose the right floor finish to get the most from your underfloor heating

Chris Stammers, Portfolio Manager for BEAMA’s Underfloor Heating Group, offers advice about pairing hydronic (water-based) underfloor heating with differing floor finishes and key specification considerations. 

Underfloor heating (UFH) is continuing to increase in popularity thanks to the system’s ability to pair with renewable heat sources and meet the latest and upcoming regulations, including offering homeowners complete control over their indoor environment. 

One commonly asked question among our members is whether UFH is suitable for pairing with particular floor coverings, especially for properties where the system will lie beneath a range of different floor finishes. Thanks to its flexibility, UFH can be used with most floor coverings, including popular and practical options such as ceramic tiles, laminate, vinyl, and even carpets. 

Whatever product type or material is selected, the primary consideration is incorporating the floor finish’s thermal resistance data and other essential parameters from the project’s outset. Understanding the thermal resistance of the floor covering(s) ensures that the system design accounts for the necessary pipe spacing and the required water temperature and flow rate to meet the heat loss demand. 

Accurate planning using all available data will ensure that the selected floor covering doesn’t negatively impact the UFH system’s performance and that both elements will work together to optimise efficiency. 

Partner with a system supplier who can assist in designing an UFH and flooring solution that ensures high performance and visual appeal for prospective buyers. An experienced provider will also ensure that the system allows homeowners to make future changes to the floor coverings, such as specifying floor probes to feed data into each room thermostat. 

Natural stone and ceramics 

Natural stone and ceramics are considered ideal floor coverings for UFH due to their density and low thermal resistance. This allows heat to transfer quickly from the pipework to the space above. All types of stone, including natural options like slate and limestone, can be installed over UFH. 

These finishes are naturally cool underfoot but, when paired with UFH, the whole floor becomes one large heat emitter, meaning the floor finish offers luxurious thermal comfort from beneath. 

Laminate and vinyl 

Vinyl and laminate flooring are also popular specification choices thanks to their straightforward installation process. Most laminate and vinyl flooring are compatible with UFH, as they are typically thin and high density, resulting in relatively low thermal resistance. However, it's always advisable to confirm with the flooring manufacturer that the product is suitable for UFH. 

Wooden flooring 

Specialist advice is needed when installing wood flooring over UFH, as wood is a natural material that can respond to environmental changes. It is crucial to confirm with the flooring manufacturer if their products have a temperature limit. If so, a floor probe will be required to ensure the heating does not exceed that limit. 

In general, engineered wood flooring is the most durable option and is less likely to react negatively to heat. Solid wood floors with a higher natural material content tend to be more sensitive to temperature fluctuations. 

Carpets 

Despite their high thermal resistance compared with natural stone and ceramics, carpets are still fully compatible with UFH systems and also offer the ideal balance of comfort and warmth underfoot. In fact, The Carpet Foundation conducted research with the Underfloor Heating Manufacturers Association that showed carpets can be used over UFH without compromising the system’s performance.  

When specifying a system to work effectively with this high-resistance floor covering, the primary consideration is gathering data and selecting widely available carpet underlay compatible with UFH. Generally, the thermal resistance should be kept below 2.5 tog when using carpet and underlay with UFH to ensure efficient system operation. 

BEAMA Underfloor Heating Group is the UK’s national trade association for UFH. Its members can be relied upon to provide quality systems and components backed up with great design, customer service and trustworthy advice.  

beama.org.uk