Why Older Cavity Wall Insulation Can Cost You More Than You Think

Why Older Cavity Wall Insulation Can Cost You More Than You Think

For many UK homeowners, cavity wall insulation feels like a job already completed. It was installed years ago to keep the house warmer and lower heating bills, and since then, it has been out of sight and out of mind. What most people do not realise is that cavity wall insulation does not last forever. Over time, it can break down, absorb moisture, or even begin causing more harm than good.

If your property was insulated more than a decade ago, it may be time to take another look. Here is why ageing insulation can quietly drain your wallet, and what you can do to put it right.

The Hidden Problem with Ageing Insulation

Cavity wall insulation is designed to reduce heat loss through your home’s exterior walls. When installed correctly and kept dry, it is one of the most effective ways to improve energy efficiency. However, the materials used in older installations, such as foam or fibre, can deteriorate with age.

Moisture is often the main issue. If water penetrates the outer brickwork, it can seep into the insulation layer and become trapped. Once wet, insulation loses its thermal performance and may start transferring moisture across the cavity, leading to damp patches and cold spots indoors. This kind of hidden damage can go unnoticed for years while energy bills steadily rise.

How Insulation Fails Over Time

There are several reasons why older insulation may stop performing properly.

• Moisture ingress: rainwater or leaks that saturate insulation materials

• Settling or slumping: insulation that has sunk or left gaps in the wall cavity

• Bridging: debris, mortar, or damp insulation connecting inner and outer walls

• Poor installation: work carried out before today’s standards and regulations

As these problems develop, insulation becomes less effective and heat escapes more easily. The Energy Saving Trust reports that up to 35 per cent of a home’s heat can be lost through uninsulated or poorly insulated external walls, which shows how significant the issue can be.

Signs Your Insulation Might Be Failing

It is not always obvious that something is wrong, but a few signs can point to a problem.

• Rooms that feel colder than they used to, particularly along external walls

• Persistent damp or mould growth, especially at lower corners or skirting levels

• High or rising heating bills without any changes to usage

• Discolouration or damp staining on internal plasterwork

• A musty smell or condensation appearing on cold mornings

If you recognise any of these, it is worth booking a professional cavity wall inspection. Even if the insulation appears intact, an expert assessment can identify hidden moisture or voids that are not visible from the surface.

What You Can Do About It

A professional insulation company can carry out a thermal imaging survey or borescope inspection to check the condition of your cavity walls. Depending on the findings, they may recommend one or more of the following:

• Insulation extraction: removing wet, damaged, or failed insulation

• Cavity cleaning: clearing debris, rubble, or bridging material

• Wall repairs: fixing external brickwork or repointing to stop water entering

• Re-insulation: installing new, high-performance insulation beads

Modern materials are more durable and moisture resistant than those used in older installations, providing a much longer-lasting solution.

In some cases, you may also qualify for energy efficiency grants or schemes that support insulation improvements, depending on your property and location.

Why Choose Cavitech

Cavitech has been helping homeowners and businesses across the country for more than fifteen years. The company specialises in cavity wall insulation, extraction, and related remedial work, including repointing and wall tie replacement. Every project is completed by trained professionals using tested materials and modern equipment to restore thermal efficiency safely and effectively.

Cavitech’s reputation for reliability is reflected in its customer ratings and industry accreditations, including CHAS and Constructionline approval. The team takes pride in offering honest advice and high-quality workmanship, helping property owners enjoy warmer, drier, and more energy-efficient homes.

If you think your insulation might be underperforming, Cavitech offers no-obligation surveys to assess your walls and provide a clear report of any issues found.

Do Not Wait Until It Is Too Late

Old or failing insulation should not be ignored. Left untreated, it can cause ongoing heat loss, damp damage, and unnecessary expense. Acting early improves comfort and protects the long-term condition of your home.

Contact Cavitech today to arrange an inspection and find out how refreshed, modern insulation can help you save energy and keep your home warm and comfortable again.