Loft insulation goes on and in between the joists on the loft floor. Roof insulation is installed into the eves of the roof. Roof insulation is usually carried out if you have converted your loft into a room. Typical roof insulation materials are rigid insulation...
A first layer of insulation is laid between the joists The horizontal beams that make up the loft floor – then another layer is applied at right angles to cover the joists and make the insulation up to the required depth of between 270 and 300mm.
Yes, it’s definitely worth it. In an uninsulated home, a quarter of all heat is lost through the roof. Insulating your loft, attic, or flat roof effectively reduces heat loss and lowers your heating bills.