The Government strongly recommends cavity wall insulation for all suitable existing houses. 'Up to half of all heat lost in an average house goes straight through the walls. Proper wall insulation can stop up to two thirds of this heat loss', says the Government energy efficiency division (within the Department of Environment, Food & Rural Affairs).

Once installed, cavity wall insulation is a permanent, maintenance-free home improvement, lasting for the life of the building, according to the government Building Research Establishment.

The Cavity Insulation Guarantee Agency provides independent 25 year guarantees for Cavity Wall Insulation fitted by registered installers.  The Cavity Insulation Guarantee Agency was established in consultation with the Government to provide householders with an independent, uniform and dependable guarantee covering defects in materials and workmanship.  Independent research has confirmed that cavity wall insulation is a very reliable process.  Problems are therefore extremely rare, but if they do occur, CIGA has the expertise to ensure that they are swiftly rectified. All CWI Installers are also certified by the British Board of Ágrement. Please click here for more information on how this helps to retain high standards of professionalism within the industry.

The benefits of Cavity Wall Insulation
Simply speaking, insulation in the walls of your home prevents heat loss in winter (and also heat gain in summer) and:

Reduces your energy consumption for heating leading to:

1. Lower heating bills
2. Lower ‘wear and tear’ on your boiler
3. Reduced Global Warming and Climate Change

There are a number of grants available which can substantially reduce the cost of installing this product and you should contact your local installer to see if you are eligible. The Energy Saving Trust estimate that due to the amount of energy you will save in heating your home that if you qualify for a grant then the installation of Cavity Wall Insulation will pay for itself within 18 months.  Ensure you take advantage of this saving now and reduce the cost of heating your home.

How does it work?
Cavity wall insulation is injected into the cavity between the inner and outer leaves of brickwork that make up the external wall of your property. An installer will do this from the outside of your property. There are a variety of different insulating materials, but they all work in the same way: by combining with the still captive air, the insulation acts as a barrier to heat loss.

A specialist contractor can install cavity wall insulation in your home and it’s surprisingly simple and cost effective. In fact, you may be eligible for a Government grant, or in certain circumstances, qualify for free insulation.

Getting your walls insulated couldn't be easier. It can normally be applied from the outside through small holes, drilled in the wall by trained technicians. The material is then injected through the holes, filling the cavity. The holes are filled in to make as perfect a match as possible with the existing wall.

This results in the air space (the “cavity”) between the inner and outer masonry skins of your outside walls being filled with insulation. Modern houses (built in the last 10 years or so) have this insulation built-in when the house is constructed, but many older houses do not.



Which Material?
The materials used for cavity wall insulation are mineral wool, u.f. foam and expanded polystyrene bead. These materials are all resistant to water penetration and will not transmit water across the cavity or from below d.p.c. level by capillary action. However, they are not a water vapour barrier and any moisture that collects within the fabric of the building is allowed to disperse harmlessly into the outside atmosphere (provided normal 'breathable' constructional materials have been used). Materials do not affect the fire resistance of the walls; and they are resistant to rot, fungi and vermin.

All the materials have equivalent thermal insulation properties. They are produced under strict quality control to ensure compliance with industry standards. Materials and processes have been well proven in this country. Therefore expertise of installation is the prime consideration. Provided you choose a member of the Association, he is bound to install according to the industry's technical standards and recommend a product suitable for your property.

Click on product material type for more details

Mineral Wool:
Your family is tucked up in a woolly 'blanket', as this material is wrapped around your home as the cavity is completely filled. Spun from indestructible rock or glass and treated with a water repellent during manufacture, it is similar to the wool used to insulate your loft.

u.f. Foam:
The foam is made on site to the British Standard 'recipe'. As it fills up all the nooks and crannies in your cavity, it immediately sets to a meringue-like consistency, trapping millions of tiny air bubbles to create a 'tea cosy' effect, and drying through the outer wall and into the atmosphere.

Expanded Polystyrene Beads:
Thousands of tiny polystyrene beads are blown into every corner of your cavity, rolling together to capture pockets of air and provide a snug 'cocoon' to keep you warm for the winter. An adhesive is normally used to bind the beads together during the process.