A number of folk here have, over the last few years, asked about the way to go about boarding an insulated loft floor to provide storage (me included!) and there have been a number of very useful suggestions depending on depth of pocket and specific situation.
One of the methods asked about has been use of legs placed on the joists to provide an elevated location to fix loft boarding. However, these always appeared to be too feeble for anything but the lightest storage. I came across a fairly new product called Loft Zone Store Floor at the Ideal Home Exhibition and must say I was impressed with the design and stability of the it. Not that I need it as I went the rockwool, light board, 'Celotex' and top board (reused) route.
Find them at
Mike