About 25% of heat is lost through the roof if the loft in your home is  uninsulated. Insulating your loft/attic is a relatively cheap and very effective way to reduce heat loss and reduce your heating bills and should pay for itself many times over. 

Insulating an uninsulated loft

If your loft  has easy access, is not boarded and has no damp or condensation problems, it should be straightforward to insulate and you can do it yourself.

You can use rolls of mineral  or eco wool insulation. The first layer is laid between the joists – the horizontal beams that make up the floor of the loft – then add another layer at right angles to cover the joists and make the insulation up to the recommended 270-300mm.

Installing loft insulation professionally in an uninsulated loft for a typical mid terraced house could cost you approx £500* and result in energy savings of around £240 per year!

Topping up loft insulation

If you already have some loft insulation but it is old and below the level of the joists then you can top it up to the recommended amount of 270-300mm. You can do this in the same way as an uninsulated loft by laying the first layer between the joists on top of the old existing and then lay the second layer at right angles to cover the joists.

If you want to board out your loft you can still top up old existing loft insulation, to the level of the joists only, and then fix the boards to the joists,

If you wish to top up to the full 270-300mm but still board out you loft then you will need to use  raise the loft floor using loft legs/stilts which are attached to the existing joists and then the loft insulation topped up to the level of the loft legs. The loft boards are then attached  to the loft legs. If you plan to use loft legs with loft boarding then it is best to get this done professionally as they will survey the loft to make sure that the loft is suitable

Topping up loft insulation for a typical mid terraced house could cost you £200-£400* and result in energy savings of around £30

Costs and savings based on Energy Saving Trust figures

Useful websites:

Energy Saving Trust