have know a few fitters to do it over the years but bad idea imo. You won’t get a full bond as the adheisve can’t soak in and would sit ontop so a weak bond. But if you want to gamble use F46 and trowel on then flatten adheisve with a medium pile paint roller sleeve.
For my heat tiles and pull...
We have gone over weak sub floors like that a few times. I did a video / picture thing on you tube of one we did.
Works well.
You could use a few types of penetrating epoxy primers
Fball SRS
Uzin PE425
Ardex PSRS
Wow that sounds well to high to soon. Most screeds I’ve worked with it’s 14 days and 1° a day to dry it out. But I’d say max 18° as the screed is still curing. Is it cement based or gypsum ?
Yeah, 2 x 10kg would be what was needed to put it down at the right microns. We tend to paint it on the bricks as well.
If just laminate I’d prob fill in the holes and put 3 coats of ardex MVS / fball F78 moisture suppressant
Or if money is ok go F77 all over. 14kg.
Or use a good vapour...