Minimum screed thickness?

Folks,

I'm wanting to put new flooring down in our kitchen/dining area.

These were originally two rooms, but some time in the distant past, before we bought the place, they were knocked into one.
They're concrete floors, but the dining area floor is about 1/2" lower than the kitchen. I got round this 12 years ago by covering that in 1/2" ply, which then made it slightly higher than the kitchen, which I then covered in 4mm hardboard. This brought them level enough for me to have a mortar taper of about 10" wide between the areas with a slope of about 2mm. This has served well with laminate for 12 years.

3 years ago we had an extension built outward from the dining area. The floor in the extension was screeded, at my request, to be at the same height as the 1/2" ply.

Now we're looking to have new laminate in the whole area and it would be good not to have to mess about bodgeing it with different thicknesses of ply etc...

Ideally I'd get the whole area screeded, but I suspect there is a min thickness for this... is 1/2" or so too thin?

Assuming it is, would one of these "self leveling" componds work, or do they have a minimum thickness too?

(As a ballpark figure, each of the three areas is approx, (very approx!), 3m x 3m.
So that's something like 27 sq metres in all.)

Lowering any of the existing levels is not an option!

Thanks in advance,

Cando.

 

Too thin for a screed... I thought so?
I'll have a think... I can probably managed to just level the kitchen area to the dining area wood using the levelling stuff. This would only be about 9sq metres. Until I get into it I can't remember which is higher, the kitchen or the diner!

If it is the dining that's currently higher I'm also seeking recommendations for a leveling compound! It would only need to be a few mm thick for the 9sq metres.

Any recommendations?

Regards,
Cando