Loose-fill insulation

Loose Fill Insulation Loose fill insulation materials which are blown into the loft are usually mineral wool or cellulose fibres, installation is a specialist job which should be left to a contractor. The materials generally have the same insulation value as rolls of loft insulation and should have a minimum finished thickness of 200mm (8in) - most roof joists are only 100 to 150mm (4 to 6 in) so some means of increasing the depth of joist may be necessary.

DIY loose-fill loft insulation materials, such as vermiculite and mineral fibre, are sold in bags and can be poured between the joists to the recommended depth.

They are easier to install than the matting if there are awkward corners or obstructions in the loft space. They also make the job easier if the joist spacings are irregular or not suitable for a standard width of matting. Again, the depth of the joists may need to be increased so that the required depth of cover is achieved.