Best Underlay For Underfloor Heating

At QA Flooring, we provide everything you could ever want in an underlay. However, it’s impossible to deliver everything all at once, which is why our range is so extensive. For example, flooring cannot both be ideal for heat insulation and compatible with underfloor heating, as underfloor heating systems require the free flow of heat to be effective. 

Today, QA Flooring will help identify the best underlays for underfloor heating – across several underlay types – so read on to find the most suitable underfloor heating underlay for your customer’s homes and businesses.

Underfloor Heating & Underlays Explained

Underfloor heating, firstly, is available in three broad categories – hydronic (using pipes and hot water) electric (using a wired system designed for smaller areas like bathrooms), and foil or carbon-film electric systems, often used under laminate or LVT. You can find different underlays suitable for different methods of underfloor heating. You should consult your underfloor heating installer and underlay provider to determine which combination is right for you.

However the underfloor heating works, it’s important that the underlay above the system allows for heat to pass through. For this, you’ll need a low TOG rating…

Why Is TOG Rating Important For Underfloor Heating Underlays?

TOG Ratings are a system in place to calculate thermal resistance, which is how hard the underlay resists heat rather than letting it pass through. These numbers will be incredibly important as you read on today.

You want TOG ratings to be as low as possible here as that represents low thermal resistance – i.e. the heating element beneath the floor can actually emit heat to the surface and you can then feel the benefit. A low TOG rating represents efficient heat transfer between layers of the floor. 1 TOG is equivalent to 0.1 m² K/W of thermal resistance.

Generally you want the combined TOG rating of your underlay and flooring type to be 2.5 or below for underfloor heating compatibility. However, some electric UFH systems may require a combined rating below 1.5 TOG – always check your heating manufacturer’s guidance.

Best Underfloor Heating Underlay For Wood Flooring

First, we’ll begin with underfloor heating underlays compatible with wood floors:

Light Traffic – Unibase

Unibase underlay provides support for laminate or engineered wood floors using a floating floor installation method. It is a lightweight material that makes it easy to handle, ensuring a smooth installation. On top of that, Unibase can extend the lifespan of your floors in a low-traffic environment, by absorbing a lot of footsteps to reduce damage to the actual floor. 

Unibase comes in three different types: Bronze, Silver and Gold. The differences between them are numerous, including thickness and moisture prevention capabilities. 

Unibase is suitable for underfloor heating, provided it’s being used in a low traffic area with wood flooring.

Medium Traffic – Quicktherm Series

The Quicktherm series has been specially designed for underfloor heating – making them easily the best medium-traffic wood underlay for underfloor heating by far. Their perforated profiles allow them to transfer heat effectively and spread it around the room evenly.

There are two variants: Quicktherm and Quicktherm Vapour. Aside from a 0.2mm increase in thickness, the vapour addition has a moisture barrier that protects your flooring from moisture rising from the subfloor. You can expect an average TOG rating of around 0.3 for both, though, so they’re both ideal for underfloor heating.

Heavy Traffic – TimberTech Elite Series

Timbertech is one of QA Flooring’s leading underlay options on the market for wooden floors. Timbertech’s main achievement is its ability to provide stunning acoustic insulation. The stats on each floor are different, but you can expect the noise of your floors to reduce by up to 32%, and impact sound up to 21dB. 

On top of this, each underlay boasts a moisture barrier, which protects your finished floors from damage caused by moisture rising from the subfloor.

We have made sure to include compatibility for underfloor heating on each Timbertech Elite model. That being said, the other models, Timbertech Neo, Timbertech Neo Acoustic and Timbertech Gold, each have TOG values higher than 0.5. This means they are less effective at heat transfer when compared to the Elite models (though still an option if you want the increased sound reduction on offer by these three underlays). Timbertech Elite has a very low TOG rating (around 0.1 – 0.2), making it one of our most heat-efficient underlays, making them perfect for underfloor heating.

Whilst this is a heavy traffic underlay, that doesn’t mean it’s not suitable for areas of low traffic – just that it would be overkill for purposes of durability, but certainly not for those who prioritise underfloor heating compatibility above all others.

Best Carpet Underlay For Underfloor Heating Systems

Next, we move on to carpets and explore the best underfloor heating underlay for this flooring type: 

Heavy Traffic – Heatwave

Heatwave is an underlay made of the purest PU foam, meaning it has an unparalleled soft feeling underfoot – maximising the comfort of your carpets. It has a thickness of 8mm, which offers comfort under foot, and it is designed for heavy traffic. 

Heatwave is touted as our ultimate flame retardant underlay for carpeted floors. With a TOG rating of 0.96, and a perforated profile it is highly compatible with underfloor heating, balancing comfort with efficient heat transfer.

Best Underlay For Underfloor Heating On LVT & Laminate Flooring

LVT flooring is soft, comfortable and has warmth of its own – but it’s possible to enhance it with underfloor heating. Since LVT and laminate relies much less on underlay to provide resistance to foot traffic, we’ll focus less on traffic in this section and more on the simple compatibility with underfloor heating systems. If your LVT already has a built in underlay, you should never use another as this could make the flooring unstable and lead to damage. This is especially true of click lock flooring where the joints can be put under too much stress.

SoundBarrier

SoundBarrier is designed to heighten acoustic insulation, essentially providing a 24dB impact sound reduction and a 31% reduction of footfall noise. It has a moisture barrier, protecting your floor from moisture rising from the subfloor, and boasts a TOG rating of 0.4, making heat conductivity easy on top of the other bonuses this underlay has. 

Best Underlay For Underfloor Heating Conclusion

All in all, we know our range of underlays are suitable for a wide range of purposes – including underfloor heating. But that also means you need to figure out which of our fantastic range is right for you.

As for the best underlays for underfloor heating, you simply need to find the underlay that suits your home best, both in terms of its underfloor heating compatibility, and the other benefits it can bring to your home based on the flooring type above.

Call our Customer Service Team on 0151 495 3434 for more advice on choosing the best underlay for your customer’s needs, or check out our trade portal for more information about our products available for bulk ordering.