Keep The House Warm

Cavity Wall Insulation

cavity insulationAs a rule of thumb most homes built after 1920 will have cavity walls. These are external walls made of two layers with a gap or cavity between them. Cavity wall insulation fills that gap helping to keep the property warm, save energy and reduce heating bills. The fitting of cavity insulation has also helped many homes by reducing the condensation on external walls and helping to increase the Home Energy Rating.

Do you have cavity walls?

As stated previously if your house was built after the 1920s it is likely to have cavity walls. If you have exposed brickwork this can give you a vital clue. If the pattern of the bricks is regular your home will probably have cavity walls. However homes with an alternating pattern will probably be solid walls.

If the brickwork has been covered by a material such as render, you can usually tell by measuring the width of the wall. Measure the width at a door or window, if it is more than 260mm thick then it is probably a cavity, there are some exceptions to this such as old stone walls which are solid and can be extremely thick.

Measure Annual Saving Carbon Dioxide Saving Per Year
Cavity Wall Insulation Up to £140 Around 560kg

These are estimated figures taken from the Energy Saving Trust

Will cavity wall insulation be suitable for you?

If you can answer yes to these your home may well be suitable:

  • Are your external walls unfilled cavity walls? Homes built in the last ten years should already be filled; this can be confirmed by checking with your local authority's building control department or by arranging for a boroscope inspection.
  • Your cavity is at least 50mm wide.
  • The masonry or brickwork of your property is in reasonable condition.
  • The walls are not exposed to driving rain.
  • The cavity walls can be easily accessed. Every part of the wall must be filled with insulation, so it's important that the installer can reach all your external walls.
  • No damp present. If you have any damp patches on your internal walls then they should not be insulated until the problem is sorted out.

Installing Cavity Wall Insulation

The installation of cavity wall insulation is a quick and easy process, usually taking around 2 hours and will be maintenance free once completed. The installer drills small holes around 22-25mm in diameter in the mortar joints at intervals of around 1.5m in the outside walls of your home. With specially designed equipment, they then deposit insulation into the cavity. Once all the insulation is in, the installer fills the holes in the brickwork. Cavity wall insulation can be made out of three types of materials: mineral wool, beads or granules or foamed insulants. All three are manufactured according to British standards. Whichever type your installer recommends it should come with a 25 year guarantee which will be posted to you shortly after the installation.

The installation process can cause some vibration so it would be wise to remove ornaments from external walls and window ledges in advance. We also recommend telling your neighbours if access to shared boundaries will be required.

Next Steps

To speak to Keep The House Warm about cavity wall insulation call 0800 118 2755 or click here to contact us through this website.