Thermal blocking occurs when the heat produced by the radiant floor heating system is trapped and has no way of escaping from the surface of the floor. This can cause the heating system to overheat in the thermally blocked area and, in extreme cases, affect the integrity of the floor covering and heating system. Thermal blocking can be caused by placing items that act as efficient insulators onto the heated floor surface and do not allow heat through.
For example, many rubber-backed rugs, shag pile rugs, bean bags, pet beds and movable furniture that stand flat to the floor or permanent furniture or features such as shower trays can cause thermal blocking. Many types of rugs and carpets can be used as long as the TOG rating is below 2.5 Togs – please refer to the ‘Carpet Floors’ section on this web site.
Furniture should have an air gap of at least 100mm between the heated floor and the underside of the furniture to avoid thermal blocking. The air gap should be ventilated and not closed off so that convection currents can distribute the heat emitted from the floor.
Heated floors are sometimes used to dry washing or other wet items such as towels, pet blankets, coats and rugs. Do not use your heated floor in this way.
Thermal blocking is not usually a problem with ceramic tiled floors as they will normally dissipate the heat from the radiant heating system around any thermal block. The system will usually tolerate small amounts of abuse but you should take care not to abuse your new radiant floor heating system too badly or it will fail and is not covered under the guarantee for such misuse.
To ensure that your radiant floor heating system works to its full capacity for the lifetime of the flooring, please avoid thermal blocking.
If you believe that thermal blocking may be an issue with your installation please call our technical department (01666 822059) to discuss your particular circumstances. We manufacture many different underfloor heating systems and will have one to suit your particular application