What insulation should I use?

What insulation should I use?

Building regulations (Part L) lays down guidelines for the insulation levels of the roof.  For cold roofs the most common insulation is mineral wool laid between the joists of the loft floor.  You will need 270mm depth of insulation material for the best effect.

If you are building a warm roof (ie a loft with living space) then the insulation is best provided by insulating boards fixed between the rafters directly under the roof tiles.