Concrete slab required or just deep leveling compound?

[BCF_Hex]

Hi all

We require a new floor in a small hall way, the (majority 60%) of the floor will be on a dirt, the other part will be over existing concrete.

The quetsion is on the dirt part can we just go :

Hardcore/MOT
DPM
150mm insulation
DPM/slip
a self leveling compound aprox 40mm (certainly not more than 50mm)


Or will we need a "concrete slab" in there somewhere?

Unfortunatly we cant get it pumped in as its too small an area, but Im sure this is how the main kitchen floor was constructed (but was pumped in opposed to us having to hand mix).

If this is an ok solution, any suggestions on a deep leveling product?

Many thanks

 

[robinbanks]

Is the concrete part already insulated? Are you joining up to it or digging it out and replacing it?

 

[BCF_Hex]

Is the concrete part already insulated? Are you joining up to it or digging it out and replacing it?

The current concrete part is actually a "ceiling" to an old cellar which is filled in (but there is a void under it for the airflow from the suspended front room floor through to the back of the house).

The dirt floor part runs up to the old cellar wall, so we will be insulating up to that wall, the insulation will bring the level about the same as the current concrete, then covering it all with the screed.

 

[robinbanks]

And there are no plans to insulate this cellar ceiling? Part of the halllway will be a concrete pad and then the cold cold world?