Loft insulation rolls feature excellent fire-resistant properties. Fibreglass insulation is naturally fire resistant, meaning that rolls made from glass mineral wool like Knauf Earthwool 44 Rolls have an A1 rating on the Euroclass scale. This A1 rating essentially means that they are anti-flammable and non-combustible. PIR loft insulation boards, on the other hand, are not non-combustible. Celotex XR4120 PIR boards have a fire rating of E, whereas Recticel Eurothane GP PIR boards have a fire rating of F. You can use a build-up of other products to improve the overall performance of your materials against fire.