raising floor level

[nafuk]

Hi, I need to raise the floor level over a cellar to match the concrete floors of the rest of the house. Current floor is regular floor boards on joists and needs to be raised approx 70mm.

I am thinking 50 mm celotex boards on top of current floor boards, then

18 mm t&g chipboard flooring, with no overlapping joists. The final floor covering will be 19mm hard wood flooring.

Any tips or advice gratefully received.

Thank you

[Rick]

That would work. The "new" floor is fully supported by the old, which I assume is in good condition.

I'd use sprayfoam to join the celotex, and fill any gaps round the edge.

Rick