Energy Efficiency - Wall and Loft Insulation

Walls lose more heat than any other part of your home - anything up to a whopping 35% of all your lost heat.

 

 

The first step towards making a saving is to find out which sort of walls you have. There are two main types of external wall, solid and cavity. Most homes built after the early 1930s have cavity walls. That means your walls have an inner and outer layer separated by a small air gap. 

 

You can usually tell which sort of wall you have by measuring their thickness at any window or door. Cavity walls are at least 300mm (12") thick, whereas solid walls are normally only 225mm (9") thick. The brick patterns are also different - compare the cavity wall (top) with the solid wall (bottom) in the picture.

 

This is a straightforward job can be done in a day. It should always be done by a professional installer, who will inject insulating material from outside into the cavity by drilling small holes in the wall.  It causes little disruption and is surprisingly inexpensive considering the amount it will save you in the long run.  It can reduce heat loss through walls by up to 60%. See grants section for information on insulation grants available.

Solid wall insulation is more complicated and costly than cavity wall insulation. A professional installer should do the work.  It involves insulating and then weatherproofing the external walls.  A layer of render or cladding, onto which a decorative finish is applied, provides weatherproofing.  It is particularly cost effective when your outside walls need repairing or re-rendering.

 

Alternatively, you could insulate the inside of your walls. You can do this yourself if you're an experienced "DIYer" and reduce the cost even further, especially if you do it when your walls need repairing or redecorating.  It is, however, still a major piece of work, and you will have to take off and refit all skirting boards, doors and window surrounds.

Various types of insulating material can be used: foam, mineral wool (rock or glass), or polystyrene beads. The cost depends on the type of material and the size of your house. 

 

Professional installers will provide a 25-year guarantee from the Cavity Wall Insulation Guarantee Agency (CIGA). This guarantees that any defect in materials or workmanship, in connection with the installation by a member installer, will be put right without charge to you.

Your home may already have some loft insulation, but if the material is thin, it won't be saving you as much as it could.  Fitting proper loft insulation is the easiest and most cost-effective way of saving energy. The thicker the material, the greater the saving.  If you have older, thinner loft insulation, think about replacing it with new material at least 270mm (11") thick. This can save around 20% of your heating costs.

 

You can get loft insulation from any DIY store or builders' merchant. Make sure that you wear the correct safety clothing, or ask an installer to do the work for you. See grants section for information on insulation grants available.

There are three main types of loft insulating material:

 

 

Only the latter two types are suitable if you are going to do the work yourself.

Heat loss is greater from certain areas such as around joists, so remember to lay the top 100mm (4") of insulation over the top of them. You will need a boarded passage to enable you to reach tanks in the loft. Don't forget to insulate and draught proof the hatch too.

 

Good loft ventilation is essential to minimise the risk of condensation and subsequent wood-rot. Most homes already have adequate ventilation, but check yours anyway, just to be on the safe side.

If you would like any further information please see the Contact us section for our telephone numbers and email address.