Having recently removed a separating wall between kitchen and kitchen-diner, there is now a gap left in the floor that needs to be filled (150mm x 3000mm).
The floor is ground floor, laid on-top of concrete and is comprised of 25mm thick polystyrene on the bottom, 18mm thick chipboard on top and a layer of plastic sheeting between.
We want to have LVT (Luxury Vinyl Tile) installed like this.
Here is a picture of the gap:
What would be considered best practice in filling this gap to prepare for LVT (Luxury Vinyl Tile)?
I was thinking to either:
Purchase some sort of ready mixed compound to pour in the gap. If so what sort of compound would be preferable?
Fill the gap with polystyrene, chipboard and a layer of plastic sheeting between. If so what to do with the small gaps between the old and new?