The First Utility guide to loft insulation
By insulating your loft or roof, you can reduce heat loss by 25% and save up to £250 a year on your heating bills – and you can even do it yourself. Simple and effective, loft insulation works for 40 years and pays for itself over and over again in that time.
Suitability and options
If your home has a sloping roof, or you live in the top floor flat and are responsible for the loft space and roof above, you can choose between two options:
Warm loft. Insulated immediately under the roof so your loft space is warm and heat retention is greater, although the installation price is generally higher.
Cold loft. Insulated above the ceiling (so, the floor of the loft) so no heat can escape from your home into the loft. Energy efficiency grants are available for this option and it’s easier to install.
Flat or dormer roofs are more difficult to insulate, so we recommend seeking professional advice and assistance.
Check whether you have any insulation already installed in your loft and, if so, how much. The recommended thickness for loft insulation is 270mm. If yours falls short of this criteria, you could consider topping it up to make maximum savings.
If your loft is easily accessible and free from damp, you can easily insulate the space yourself using rolls of mineral wool insulation cross-laid regularly between the joists. If your loft space has damp problems, you should first seek professional advice because insulation could exacerbate the effects.
If you intend to use your loft for storage, you should consider hiring a joiner to put in some cross-joints. This means any boarding you put down will be able to accommodate the full 270mm of insulation.
Similarly, if your loft is a living space, opt for insulating the roof with insulation boards instead. These boards should be cut to size and fitted between the rafters and even over them if the rafters aren’t very deep.
If you have a problematic loft space filled with obstructions and irregular joists, loose-fill insulation could be an ideal option for you.
Having loft insulation installed in a typical three-bedroom, semi-detached house with gas central heating costs around £300. It will take less than two years to pay for itself through energy savings.
Loft insulation also qualifies under the Green Deal – a scheme which offers loans to people who meet a criteria so they can make energy-efficient home improvements.
For more energy saving tips and advice, be sure to visit the First Utility blog.