Let’s Talk Tog

We may all be taking advantage of the beautiful summer weather, but our customers are specifying for the winter ahead. So we thought it timely to address an increasingly common question; are Jacaranda’s carpets suitable for installation over underfloor heating? The quick answer is yes, with a more detailed explanation below.

Which Jacaranda products are best for underfloor heating?

Research by The Carpet Foundation in conjunction with the Underfloor Heating Manufacturers Association concluded that a tog of 2.5 (carpet + underlay) is a realistic maximum limit for underfloor heating.

The good news is that many of Jacaranda’s ranges fall comfortably under the 2.5 tog level and with lots of underlays all coming well under 1 tog there is plenty of choice. All our hand-woven pure TENCEL™ carpets renowned for their incredible silk-like shine and eco-friendly credentials have a tog rating well under 1, which means heat will transfer quickly from heating to room.

Even with wool, renowned for its insulating properties, there is plenty of choice. Our deep pile, hand-woven 100% wool Willingdon has a tog rating of 1.4. Whilst our flatweaves have surprisingly low tog ratings for pure wool carpet all falling between 0.8 and 1.8 tog.

The tog rating for all our ranges can be found on our website product pages.  Browse our carpet ranges suitable for underfloor heating.

The detail…

Tog stands for ‘Thermal Overall Grade’ and is a unit of measurement used to calculate the thermal insulation of a product. Essentially the higher the tog rating the slower the heat can pass through.

Manufacturers will normally recommend a maximum tog value that you should lay over their heating systems. They may state that carpet must have a thermal resistance of no more than 1.5/1.7 tog, but it is genuinely not that simple.

The laboratory test method used for tog was designed to predict insulation or the prevention of heat loss downwards through a floor with conventional heating such as radiators. However, The Carpet Foundation in conjunction with the Underfloor Heating Manufacturers Association carried out a research project which demonstrated that it had much less value when considering the reverse situation with underfloor heating. They tested 5 different carpet types with togs varying between 2.6 and 3.4 in a 4m square by 3m high test chamber. The results showed that none of the carpet/underlay combinations interfered with the efficient warming of the airspace in the room above.

They now advise carpet manufacturers to subtract a conservative 1 tog from the tested thermal insulation to provide a measure of the ‘real’ thermal insulation of their product when it is used over underfloor heating systems. Please note Jacaranda’s tog ratings shown online do not have 1 tog subtracted, if this is factored in our carpets are even more suitable. carpetfoundation.com/underfloor-heating/