Advice on raising floor

[ponx54]

Hi there. I need to raise the floor level on a concrete floor by 1cm in order to provide a run off to a pre installed floor drain in a walk in shower room. I was thinking of using 6mm pro warm sheets. In their video they have the sheets being laid on a flat bed of adhesive. But is there any problem using a 10 mm u shaped notch trowel to put them down. Or would it be better to latex the area to 1cm. Can you use ceramic tile adhesive on top of latex or does it need special priming..