Floor insulation with electric underfloor heating — | BOKKA
Floor insulation for electric underfloor heating — project near Kraków
In a timber-frame house located in the vicinity of Kraków, a comprehensive thermal insulation of the ground-floor slab was carried out, integrated with an electric underfloor heating system. The investor opted for an energy-efficient solution combining a thin insulation layer with high thermal performance — a critical requirement for lightweight timber-frame buildings, where every centimetre of partition thickness matters.
Design challenge
In timber buildings, floor insulation must offer a very low thermal conductivity coefficient and high compressive strength — particularly beneath a screed embedding electric heating mats. Conventional insulation materials such as mineral wool or EPS would require a significantly thicker layer, conflicting with available room heights and threshold levels. Additional requirements included dimensional stability under service loads and resistance to elevated temperatures generated by the heating system.
Solution applied
termPIR® PIR boards were used as sub-screed insulation — a thin, rigid polyurethane panel with a low λD value (approx. 0.022 W/m·K), delivering very high thermal performance at minimum thickness and achieving excellent U-values for the floor assembly. The boards were laid directly onto the prepared substrate with tight butt joints, followed by the heating-mat layer and a finishing screed. The rigid PIR structure performs excellently with electric underfloor heating, limiting downward heat loss into the ground and directing the heat flux upwards into the occupied space. The fire classification of the PIR core is also well suited to residential applications.
Result
The investor obtained an energy-efficient floor with a slim overall build-up and rapid thermostat response time. termPIR® polyurethane insulation proved to be the optimal sub-screed solution for timber construction — combining low weight, high thermal efficiency and straightforward installation. BOKKA supplies termPIR® boards across the Małopolska region and the whole of Poland.
Need help specifying PIR boards for an electric underfloor heating project? Contact us.
