Build height is the height required for an underfloor heating system to be laid beneath the floor covering. Most systems, such as Heat Mat’s undertile heating mats and cables and in-screed cable add not build height to the construction as they are absorbed into the tile adhesive or screed layer.
Other systems, such as Heat Mat’s Underlaminate System do require an increase in build height however even with this system it is only 6mm including the insulation. The electrical underfloor heating systems requiring the most additional build height are heating mat applications which require a levelling compound layer on top of them, for instance for use beneath carpets. Even in these circumstances the additional build height requirements are no more than 12mm.
Water based underfloor heating systems require much greater build heights than electrical underfloor heating which is why they are not often used in renovation work. With water based systems the build height requirements are often above 50mm.