A loft hatch can lose much heat from the house through the roof. It can be insulated using a variety of materials, and ideally the insulation must include some form of draught excluder at the edges. There is a variety or products on sale in do it yourself stores in Britain, but it is always possible to make your own.
The reason for insulating the hatch
Heat rises. So, if you heat your house, the heat will rise up the staircase and pass through the ceiling and out through the roof. Loft insulation prevents this happening, but many people do not insulate the loft or attic hatch. Thus, energy experts believe that up to five percent of your heat can be lost through the hatch.
The difficulty with insulating a hatch is that we tend to get loft insulation in rolls of rockwool. This means that we cannot just lay a roll over the hatch, as this will impede access to the loft. The trouble with rockwool is that you cannot cut a piece and just nail it down, as nails will not stick to it, and a small piece may not be stable and be blown off by draughts which will find their way into the loft from under the eaves.
Some companies supply loft hatch insulators. These are rigid structures which can be fastened onto the hatch. B and Q and Wickes both advertise them. The advantage of commercially produced loft hatch insulation is that it will have draught proofing built-in. This deals with the problem that heat will leak up through the sides of the hatch, so in any loft hatch insulation draught proofing is necessary. Commercially produced loft or attic hatch insulation must be guaranteed fireproof.
However, it is possible to make your own. If you do so, ensure that all safety standards are met. You must not use flammable material which could spread fires through the loft or attic space. Some people suggest getting a large plastic bag bigger than the hatch space and filling it with insulating material. The overlap will provide the draught exclusion that you require.
Insulation materials can include rockwool, which we use in our loft insulation anyway. Some people suggest using recycled plastic bottles, though whether this is safe in a fire remains uncertain. Some DiY enthusiasts might fill such a bag with polystyrene. The bag can be fastened onto the loft hatch with glue. Do not use superglue, as you might want to take it off sometime.