Introduction

Laying loft insulation is not necessarily an easy task, however with careful preparation and the correct choice of material for your particular loft space, it’s a job well within the scope of most able DIYers.

• If you do have any doubts about your ability to successfully apply insulation to your loft space, its always best to hire a professional to do the job for you.

Considerations

To ensure that the insulating material is doing the best job of reducing heat loss, it is worth considering the following when deciding which material is best for your requirements;

There are three types of British Standards approved materials; Mineral wool/fibreglass matting, Loose fill mineral fibre, and Blown mineral wool or blown cellulose fibre.

The first two are designed specifically to allow DIY installation, however ‘blown’ products require purpose-built blowing machines and specialist knowledge to install and as such should be applied by a specialist only.

It is important to only use British Standards approved products, as not only are these materials approved for use in lofts spaces but they also meet the current fire safety ratings within the building regulations.

Matting or Roll insulation

Matting (or quilt) loft insulation is installed by rolling out in the loft space, and can be applied both between the joists and on top of them. The rolls are available with a variety of thicknesses to meet your particular need, note though that the rolls are usually only available in 16in wide lengths, which is ideal for modern lofts with even joists but not necessarily for houses built before 1930.

If you are considering laying insulation across the joists, remember you will not be able to walk on the material afterwards. If you wish for a more functional loft space and the correct depth of insulation, then you will need to raise the height of the joists with suitable lengths of timber, and lay the material between them. It is also advisable to lay boards down in the parts of the loft you wish to use, this gives a nicer surface and prevents any possible dammage to the ceiling below.

• Rolled insulation materials

Loose fill insulation

Loose fill insulation products are available in bags and can be poured between the joists to the required depth. They are easier to install than matting or rolls, particularly if there are awkward corners or obstructions in the loft space.

Loose fill insulation also makes the job easier if the joist spacings are irregular or not suitable for a standard width of matting. Note; the depth of the joists may need to be increased so that the required depth of cover is achieved.

Loose-fill insulation is not generally suitable for draughty loft spaces as the air movement can shift the material around and reduce the insulating effect. If a floor is laid in the loft, as in a loft conversion, then this will prevent movement of the material.

• Loose-fill loft insulation

Alternative Insulation Products

Unlike more traditional forms of insulation, such as fibreglass and mineral wool, organic materials require very little energy to manufacture, which means that their impact on the environment is incredibly low. In fact when used as an insulator, the energy saved can have an incredibly postive impact to the environment, which in todays environmentally conscious climate is becoming increasingly more relevant. They are also almost always non-toxic making them safe to handle and thus easier to install.

• Organic insulation materials

Insulation derived from naturally occuring materials can make an attractive alternative to the more traditional fibre glass/mineral wool approach. As well as their excellent heat insulation properties they are also generally safe to handle, which makes them much easier to install in ceiling and loft spaces. Unlike organic materials though, natural insulators require some considerable energy to produce which means that they have a high embodied energy count.

• Natural insulation materials

Working in the loft space

Before starting work in the loft, ensure you have;

• Full loft preparation check list

Further information and useful links

• Making structural changes to your property
• Successfully damp proofing your home
• More walls and ceilings topics
• Building works topics

• Find a Insulation Installer near you
• Find a Builder near you

• National Insulation Association
• Energy Savings Trust (est.org.uk)
• Cavity Insulation Guarantee Agency (ciga.co.uk)
• Party Wall Guidance (rics.org)
• Impact of the Party Wall Act 1996 (communities.gov.uk)