Although it is not essential to have insulation directly under the heating mat or cable, we do strongly recommend it.
Insulation will reduce your running costs and shorten the warmup time of your underfloor heating.
What insulation should I use?
For our UltraTec Under tile heating cables and MD underfloor heating mats we always recommend that either our Ekoboard insulation boards or Thermopanel insulation boards are used.
The Ekoboard insulation board is suitable providing that the floor base is level, load bearing and there is no movement in the floor.
If there is a chance of movement, or the floor is uneven we would recommend that the Thermopanel insulation boards are used as an alternative to Ekobard.
With insulation board thicknesses available from 6mm to 60mm the insulation boards you choose for use in your project will depend on the depth you have available, though of course the greater the depth of insulation, the more efficient it becomes -though of course any insulation whatever the thickness is better than no insulation.
For our WoodTec under laminate and engineered wood system and our FloorTec under carpet and vinyl system our 6mm Izotherm insulationmustbe used along with a vapour barrier.
For our VCD17 In-Screed heating system we would always recommend that the heating cable is installed directly onto a foil backed Celotex or Kingspan insulation board, the thickness of this board depends on building regulations and the depth you have available.