If you do not know how to put the rafters, then we advise you to call a specialist. He will put you rafters, and in the meantime you put cotton materials in the gaps between the rafters on the crate. Does not forget about the use of a vapor barrier film that will protect the insulation. When choosing a heater, it is worth relying on the design features of the roof of your house, as well as the material that it is covered. In the event that your house has an attic, be sure to pay attention to the insulation. If you are a happy owner of a house with an attic, do not limit yourself only to heat, steam and waterproofing, be sure to pay attention and sound insulation. If your attic is not insulated sufficiently, you will have to spend more money on heating the premises.
If you have a pitched roof, it is worth using soft cotton materials that have a density of not more than 50 kg/m layers of thermal insulation material should be placed symmetrically.