How To ... Install Cavity Wall Insulation
Written by BBC Green

Cavity wall insulation sounds painful, but it's actually one of the simplest and most cost effective ways to green your home.

Cavity wall insulation is an effective way to improve the energy efficiency of your home. This guide tells you to how to install it so you can get the maximum benefits and save money on your energy bills.

In this article:

• What are the benefits?
• How much will it cost?
• What insulation should I use?
• How do I get it installed?
• What are the benefits?

In most homes built after 1920 the walls are made up of two layers with a small air ‘cavity’ in between. If you have an unfilled cavity then you could be losing a considerable amount of the heat from your house to it.

In fact, the average house could reduce heating costs by 15 per cent simply by installing insulation in the cavity.

How much will it cost?

The average cost is around £500 but it depends on the amount of material you need to fill the cavity, so it will be more expensive for bigger houses. However, it could save £90 a year from the heating bill of the average house, so could pay itself off in little over five years.

What insulation should I use?

There are three main types of insulation material;

1. Mineral Wool
2. Urea Formaldehyde Foam
3. Polystyrene Beads

They all share the ability to remain sufficiently stable, so can remain in place for the life of the building. These materials all have low thermal conductivity, are non-combustible, resistant to water penetration and allow moisture to escape through the wall.

Which material you decide to use is up to you. Your installer should be able to help you choose. For a more eco-friendly insulation you could use sheep’s wool, hemp, flax, cork board, cellulose (from recycled newspaper) or straw. However, many need a larger access space to be installed, can be susceptible to fungus and pests and often need to be replaced in time.

How do I get it installed?

You need to hire someone with experience and the right equipment to do the job. There is a list of accredited installers on the Cavity Insulation Guarantee Agency (CIGA) website.

It will usually only take two to three hours to install cavity insulation and will cost around £500 for the average home. You may also be eligible for a grant to help towards the cost.

To find out more visit http://www.bbcgreen.com/Home-Garden/Heating-Insulation/how-to-insulate-cavity-wall