Cavity insulation is one of the most cost-effective ways to improve the energy efficiency of your home. It can be fitted in most homes, even those built before 1920 that have cavity walls.
Unlike continuous insulation, cavity insulation is located between framing members and may be bridged by major structural elements like service openings. Gaps, voids, and degradation in cavity insulation will subvert its insulating effectiveness.
Cost
Cavity insulation is a cost-effective way to reduce heat loss from your home. You can save up to PS145 a year in energy bills, and the investment usually pays for itself in three years. The price of installing cavity wall insulation depends on the type of property and materials used. However, you should be aware that the gap in the wall must be inspected before insulation is filled in to ensure that there are no leaks or damaged brickwork.
There are several types of cavity wall insulation available in the market, including polystyrene beads, mineral wool, and glass fibre. Each comes with its own pros and cons. Polystyrene beads are the most popular choice and are available in white, grey or black granules. They are one of the best insulation materials and cost between PS18 and PS22 per m2. Mineral wool, on the other hand, is made from recycled igneous rocks and can be easily installed in the wall cavity, while also being fireproof. It is also rot-resistant and costs between PS13 and PS18 per m2.
Effectiveness
Cavity wall insulation is one of the most cost-effective ways to minimise heat loss, saving on energy bills and reducing your carbon footprint. It is also a great way to protect against future energy price increases.
When choosing an installer, look for one that is a member of the CIGA or the National Insulation Association. These companies are vetted and will provide a guarantee for their work. This means that you can be confident in the quality of the installation and in your peace of mind that your property will be well insulated.
Mineral wool insulation is blown into existing cavity walls to form an effective, energy efficient insulating layer. It is available in a range of thicknesses to suit different cavity widths. It is also quick to install, and can be cut to fit around different joist configurations. It is a highly durable product and is fire-resistant, making it a popular choice for builders.
Durability
Generally, cavity wall insulation lasts for the lifetime of your property. However, it is important to choose a reputable installer and check that they are registered with the Cavity Insulation Guarantee Agency (CIGA). CIGA provides a 25 year guarantee against problems caused by incorrect or faulty installation of CWI.
The most popular material used to insulate cavity walls is mineral wool fibre, although polystyrene granules or beads and polyurethane foam are also available. Mineral fibre is blown into the cavity using air pressure and a mix of adhesive. It is a quick, easy and cheap option.
Problems with EPS beads can include gaps forming between them, which leads to heat loss and dampness. This is particularly problematic if you live in an area with frequent wind-driven rain such as Ireland, Wales and Western coastal areas. Moisture soaked EPS beads can also lose their insulating properties, leading to mould infestation and structural damage. Fortunately, these problems are rare if you use a reputable installer.
Installation
Cavity wall insulation is a simple and cost-effective way to make your home more energy efficient. A third of your heating escapes through the walls, and insulating them can help you save money on energy bills. It is a quick and easy process, and usually takes only about half a day.
It is important to choose a reputable installer. They should be registered with a professional body such as CIGA and offer a guarantee for 25 years. This ensures that the job is done properly and is not prone to problems such as damp bridging.
EPS beads and granules are blown into the wall cavity with a mix of adhesive, creating an insulated barrier within the walls. It is suitable for most homes, and is often used in free cavity wall insulation schemes. Blown mineral fibre is another popular form of insulation. It is best suited for standard-sized cavities and can be used in timber-framed houses and brick-built homes.
