What's the best loft insulation?

[betterwhenthesunshines]

We had lots of (fibre glass??) loft insulation but had a bad mouse infestation problem and most of this had to be removed to make a clean enough space for contractors to work in while rewiring was done.

I need to replace the insulation ( not eligible for free insulationf from energy suppliers as far as I can make out) so what is the best way to do this?

Fleece / fibre rolls?
Reflective foil padded stuff?

Attic space is unboarded and I think our building regs require 10 inches of fibre glass stuff, but this will be above the rafters and make any access difficult as it will be difficult to see where to walk!

[tricot39]

The glass fibre rolls are probably cheapest and easiest to install via the loft hatch. Normally you would fill the void between ceiling joists and then roll the top quilts across at 90degrees to minimise gaps. If you want boarded/storage areas you need to add in some joists over the top of the existing ones (ie within the depth of the top quilt). Also keep the quilts back from the eaves ro ensure ventilation is maintained in the roof space.

If you opt for a foil backed polycianurate (sp?) board like kingspan you can lay that over the joists and for light loads lay boarding directly on top. But if access is tight chopping up the insulation boards to get them in place might the whole thing impractical - and also riddled with gaps compromising the insulation.

I would go for the former if i were you.