Improving on 10cm loft insulation - quick wins?

[DIYNovice1979]

Hi,
My loft is mostly boarded (around 90%), it's got the standard 10cm loft insulation. I'd like to improve on this and was wondering if there's a quick and simple method I can use. I believe the best answer is to raise the floorboards by another 20cm and add a bunch of insulation, however that's going to be a ton of work and I don't have the time or apetite to do it.

We're currently storing some old carpet in the loft and I was wondering whether laying it on top of the existing floorboards would help with insulation? Alternatively is there a material\solution that would simply fit on the existing boards to provide insulation?

Ideally I want to avoid the hassle of taking up the boards, drilling, filling with insulation and re-screwing them down as it'll either take too long or cost too much.

Thanks in advance

 

[cdbe]

PIR sheets, as thick as you can afford, with thin plywood or hardboard on top.

 

[DIYNovice1979]

Do you need the plywood/hardwood on top or could you just walk on the PIR sheet?

 

[mikeey84]

Pir is pretty resistant to spread loads, but doesnt perform well with point loads, so it ideally needs something, doesnt need to be more than 6mm ply, just to protect it