Have a fair sized basement under a mates new build coming up in a few weeks that ill be doing out in Karndean (< his choice) and it has underfloor heating, what prep would you use? Last one I did was in NA and F48 whereas ive known 1200HD/F44 to be used... What would/do you use?
Deffo use HT glue over UFH as thats what KD recommend. I would also be checking the slabs RH to see if it needs a DMP
I'd be wary of using a dmp on ufh in a basement Double whammy chance of hydrostatic pressure blowing it off the floor. Make sure it's dry then a 8-14mm hit of fibre reinforced compound. Dry fit then wet set in karndean universal / Uzin ke66
