Ashley

I want to add some insulation to our loft hatch door - I think it is responsible for losing a lot of heat from our 1930s 3 bed house. It's a very basic hatch: the hinged door (swinging down) is a 12mm thick chipboard sheet with no additional insulation. I'm thinking about attaching some kind of insulating board (perhaps about 50mm thick) to the top side of the door, cutting as necessary to make sure it doesn't foul the ladder. Can anyone suggest a suitable and fire safe insulation material, though? Eg searching Amazon for "fire retardant polystyrene board" gives hardly any hits - I'm not sure what to look for. Any advice much appreciated.