The use of ARDEX E 25 Mortar Admix in conjunction with ARDEX sub-floor smoothing compounds is advisable in specific situations: when high abrasion or point load resistance is necessary, for temporary wearing surfaces, when a floor paint or thick coating will be applied later (ensure compatibility and conduct a trial application), and when the floor has underfloor heating. For floors with underfloor heating, it is essential to turn off the heating for 48 hours before applying the screed, leave it off for another 48 hours after application, and then gradually increase the temperature.