Was looking to board a small area of my loft while installing insulation and came across this stuff, subsidised at B&Q.
Cost is £3.28 per board with current 10% off, normal cost is £17.36 at B&Q for 4?
Basically - you put 100mm of normal insulation between the joists, then 2 of these on the joists, one on top of the other, and it gives you the equivalent of 270mm insulation BUT you can store stuff on top of it. It can't be walked on unless you put loft chipboard on top, but for light objects or in conjunction with loft chipboard, it's probably an easier way then raising the joists above the level of the extra insulation.
Space Board enables you to fully insulate your loft and use a proportion of the area for storage. It is Extruded Polystyrene that has high compressive strength. Can be used over existing loft boards. With 100mm insulation under existing loft boards and 2 layers of Space Board on top, this area will now meet the required U-Value equivalent to 270mm of Glass Mineral Wool insulation. It can be covered with additional loft boards for areas of high traffic.
500mm x 1200mm x 50mm
* Lightweight yet high compressive strength
* Sized to get through loft hatches
* 100% recyclable
* Not designed to support a persons weight, unless covered or supported by a chipboard loft board
* Greatly improves the thermal efficiency of your home
* For DIY use only - This product is subsidised under the Carbon Emissions Reduction Target. It is not for use in new buildings.
* Further subsidies cannot be claimed by professional installers on this product. This product is limited to 100m2 per customer.