Loft boarding with 400mm insulation

[nacnudus]

Is it possible to board a loft that has 400mm of insulation? The joists are 120mm high.

LoftZone would raise the boards to 404mm, leaving only a 4mm air gap instead of 50mm.

Loft Leg XL would raise it to 425mm, leaving only a 25mm air gap.

Could I put a block of wood between the joists and the LoftZone/Leg? Or should I lay down whole beams crossways?

Thanks.

 

[RandomGrinch]

Hi,
Theres an interesting thread here:
https://www.diynot.com/diy/threads/...ed-between-loft-insulation-and-boards.161733/
suggesting why an air gap is needed.
I personally have the Loftzone storefloor and found it really straightforward and quick to install. But I have nowhere near 400mm of insulation!
Blocks to lift up the legs would be quite unstable. I think cross beams would probably do the job better.