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Home & garden.

Types of loft insulation

Find out more about the different types of loft insulation, their pros and cons, and how to install them.
Which?Editorial team
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Use our expert advice to help you choose the right type of loft insulation for your home and budget.

Installing loft insulation can cut your energy bills by up to £315 each year and help keep your home warm.

Find out how much you should expect to pay for loft insulation, and how long it takes to pay for itself, in our guide to loft insulation costs and savings.

Loft insulation types

There are several different types of loft insulation to choose from and a variety of loft insulation materials available:

Batt or blanket loft insulation

This is probably the most common type of insulation. It is available in rolls of foil-backed felt, rock, glass or mineral fibre.


  • Straightforward to install yourself.
  • Some brands use recycled glass or sheep’s wool (which is non-irritant).
  • Good for insulating accessible spaces such as exposed wall cavities.


  • Some materials can irritate the skin, so you'll need to wear proper protection.
  • Sheep’s wool is a more expensive insulation option.
  • Rolls of blanket can be too bulky to fit in small spaces or around obstructions.

Find out how to fit blanket loft insulation.

Loose-fill loft insulation

This is made from a variety of granular or lightweight materials such as cork granules, mineral wool or cellulose fibre. Greener types of loose-fill insulation include recycled newspaper.


  • Fits easily between irregularly spaced joists or around obstructions.
  • Useful for topping up existing insulation in attics.


  • Can come loose in draughty lofts.
  • Safety equipment and protective clothing are needed during installation.

Find out how to fit loose-fill insulation.

Sheet loft insulation

Sheet insulation is designed for insulating the sloping sides of the roof and comes in the form of firm boards. 

Some sheet insulation boards are available with a fire-resistant, moisture-resistant or decorative covering. It can be ordered precut to specific sizes, usually at an additional cost.


  • Greener sheet loft insulation options include cork, straw and wood board.
  • Excellent for insulating loft conversions.
  • Can be covered with plasterboard for an attractive finish.
  • High insulating value per unit thickness.
  • Some boards come with their own system of attachment.


  • Synthetic sheet insulation materials use large amounts of energy during production.
  • Can be more expensive than other types of loft insulation.

Find out how to fit sheet roof insulation.

Blown-fibre loft insulation

You’ll need a professional contractor to install blown-fibre insulation - the insulation is blown into the gaps between joists.


  • Quick and easy to install when done by a professional.
  • Greener insulation options include recycled paper or wool.
  • Ideal for insulating areas where access is difficult.
  • Light and convenient to handle and cut.


  • Can be more expensive than other types of loft insulation.
  • Not recommended for insulating draughty lofts.

Find out how to fit blown-fibre loft insulation.