Engineered hardwood floor over liquid screed - Glue? Primer?

[hellopaul2]

Hello,
I have 150sq.m of liquid screed floor (70mm thick, poured about 3 months ago, laitance removed) with liquid UFH (first switched on - low heat - yesterday!), and I'm planning to install an engineered hardwood floor over it. I've had a couple of conflicting opinions from fitters:

Fitter 1 has said we can just glue the wood directly to the floor, using Rewmar adhesive (this, I assume) which claims to be "suitable for sticking down any species of wooden flooring to almost any subfloor".

Fitter 2 has said that we need a latex screed and a sealer, THEN we glue the floor down.

Does anyone have any experience of the perils of a glued wood floor on a screed and if we are wasting time and money doing the extra work, or if it's essential? I'm wondering about a happy medium: I buy a few tubs of primer (such as this), roller it on, then once it's dry (only takes 45-60 minutes per coat apparently), glue the floor down.

Any thoughts, anyone, please?

Thanks,
~ Paul

 

[dazlight]

Fitter 2 is correct.
You need to turn heating off and do a moisture test with a hydrometer
Needs to be a Reading under 65% RH

 

[hellopaul2]

Thanks, @dazlight . Yes, I know about the "under 65%" moisture level - I've been doing hygrometer tests (I have borrowed 3 meters); it's currently around 76% (in darkest recesses of the floor) after 24 hours. I'm wondering what would be the reason for a latex screed AND sealer - surely they'd both do the same job? The screed is nice and level (I checked may areas with a 2m long level and the undulations were non-existent).