Loft insulation/loft storage

[Steve_D]

If I followed the recommendations on insulation thickness in my loft it would be well above the existing rafters and make it impossible to use the loft for storage.
Does anyone have any ideas how to resolve this without resorting to building a raised floor above the existing rafters.

I was wondering if polystyrene (inflammable) or some other foam blocks could be put down with some chipboard on top.

Steve

[GreenV8S]

I've seen insulating foam panels which go over the existing flooring and are strong enough to walk over, but they aren't cheap.

[UpTheIron]

The "recommendation" won't actually be thickness but the insulating properties of the material. You can get thinner insulation that insulates as well as the thicker stuff...the catch is it costs more.

[Tom_C76]

Something like celotex would give the same insulation value as double the thickness of glass fibre, but unless you lay it across the joists as well you'll still have air gaps.

I decked mine out using chipboard on a load of 2nd hand 3x2 timbers reclaimed from a site. The 3x2 runs perpendicular to the trusses and keeps the insulation more or less in tact.

[VxDuncan]

As suggested - 100mm of Kingspan / Celotex will give you equivilent of roughly twice that of standard glass fibre loft insulation, obviously you can get different thicknesses of sheet to match the depth of you rafters. You will need to board over though as the surface is easily damaged, and it ain't cheap - 50mm thick stuff is ca. £25 for an 8'x4' sheet (cant remember about the thicker stuff). The other thing to watch with poystyrene sheet (not sure about celotex etc), is that the insulation on any electrically cables doesn't touch it as it break down over time. That's over and above the requirement to keep them from getting too warm by running them over, not under the insulation.