As with carpeted floors, there are two options for safely heating vinyl or Karndean floors, one by covering the heating element with screed or levelling compound to help spread the heat evenly across the floor and another option is to use our combymat system together with overlay boards, without any wet trade required.
If you are laying a screed then you can use an in-screed heating cable with a maximum output of 160W/sqm, which provides a very stable temperature, and is the most cost effective method of installing underfloor heating.
If you are not laying a screed then we recommend laying our 160W/sqm heating mats and covering these with at least 12mm of flexible self-levelling compound to help spread the heat. This installation method ensures a low build height and provides a fast-reacting system.
If you have any questions or are considering another type of flooring please call our technical department to discuss options on 01444 247020 or contact us here.
Heat Mat’s recommendation for vinyl rolls, sheet vinyl and vinyl tiles (including LVT such as Amtico and Karndean)
Vinyl flooring in its many forms is a flexible and hard-wearing floor covering that is well matched for use with an electric underfloor heating system. There are several system options for heating beneath a vinyl floor and the key to trouble free use is ensuring that the flooring is suitable for underfloor heating and that the temperature of the floor does not exceed the recommended levels.
With a vinyl floor the key aim of a system is to ensure that the heating from the UFH is spread out before it reaches the floor surface; this ensures even heating of the vinyl which helps guard against shrinkage or discolouration of the flooring. Heat Mat’s most commonly recommended floor build up for a vinyl floor is our 160W/sqm heating mats covered with a 12mm self-levelling compound. This is the gold standard for heating this type of floor covering and has a design life of over 50 years.
In situations where wet trade is not possible an alternative to the levelling compound method is to use Heat Mat’s 150W/sqm Combymat covered with overlay boards to create a completely flat floating floor surface. This method takes up 13mm of build height, so only 1mm more than the levelling compound method, and is a good alternative when wet trade needs to be avoided or where a floating floor must be maintained.
The final option of heating beneath vinyl is to use an in-screed cable system running at up to 160W/sqm beneath a 55mm plus screed. This option is only viable if a new screed is going to be laid and it is not a direct acting heating system which means that it will take longer to warm up, but also longer to cool down; it results in a more stable room temperature than direct acting systems such as those noted above.
Whichever system is used it is important to limit the floor temperature to avoid the system overheating and the normal recommendation from vinyl floor manufacturers is to limit the floor temp to 27 degrees Celsius. If this is what they recommend then we suggest setting up your underfloor heating controller to limit the maximum floor temperature to this level, however if you find that this floor temperature limit prevents your room reaching the desired temperature you can raise the maximum floor temperature up to 32 degrees Celsius one degree a day without any major risk to the floor. In 20 years of testing Heat Mat is yet to find any vinyl floor that cannot comfortably cope with 32 degrees Celsius without any adverse effects.
When heating a vinyl floor, it is important to avoid any major thermal blocks over the flooring as these will trap heat and can lead to hot patches on the floor that may cause the floor to expand and contract unduly. Examples of thermal blocks include floor-fixed furniture without an air gap of at least 25mm beneath it, dog beds, rugs, and mats with thermal or rubber backings and any other item that does not allow the heat to escape from the floor. The 160W/sqm mats with levelling compound and the in-screed cable options are most suited to coping with minor thermal blocks whereas the Combymat system is less capable of dealing with these.
In all circumstances our recommendation is to confirm with the manufacturer of the floor and the floor covering installer that they are happy with the chosen method of installation and that the floor covering is suitable for use with electric underfloor heating installed in this way. Heat Mat are yet to find a vinyl flooring manufacturer who is not happy for their flooring to be used above any of the above types of system as long as the maximum floor temperature is limited.
Very rare issues such as discolouration of the vinyl floor, shrinking of elements of the floor (creating gaps beneath tiles) and delamination of the vinyl tiles from the floor base do happen. These issues are invariably caused by the installation of unsuitably powerful underfloor systems beneath the flooring (above 160W/sqm) or the levelling compound covering the underfloor heating being too thin or non-existent. Large thermal blocks can also cause issues as can setting the maximum floor temperature limit too high, although in Heat Mat’s experience this is likely to need to be set close to 40 degrees Celsius before issues become apparent.