Cavity wall insulation problems

The problem with cavity wall insulation

admin Damp


Insulation providers have traditionally struggled to persuade people to spend their own money on well-designed, properly installed energy saving measures. To counter this, various government subsidies have been made available over the past twenty years.

However, this has created what the Property Care Association describes as a ‘gold rush’ mentality amongst some speculative contractors. As one scheme starts, contractors strive to try and grab as big a share of the pot as quickly as possible. Firms must move quickly to cash in: expanding rapidly and hiring sales teams motivated by commission to pull in volume of customers. Quality of installation and the building’s suitability become secondary considerations. Instead, volume, speed and making money quickly become the drivers for some contractors.

The problem

When retrofit cavity wall insulation is installed into a property that is located or built in a way that means it should not have the cavities filled, or if the work is undertaken incorrectly, the first and most obvious sign of a problem is nearly always internal dampness.

For example, where cavities are discontinuous or are crossed by solid elements such as floor slabs, ‘cold bridges’ can remain. Before the insulation was added, the temperature difference between these bridges and the wall may have been relatively small. After the wall cavities are filled with insulation, these un-insulated elements may be significantly colder than the surrounding walls. This, combined with a draughty house, can create ideal conditions for condensation and mould.

In other cases, homeowners are reporting new problems with damp. Here, insulation has stopped both warm air and moisture escaping. Without air exchange through controlled ventilation, the moisture has nowhere to go, leading to a rise in humidity levels rise and inevitably, the growth of mould.

The PCA see the rise of opportunistic insulation removal companies as another symptom of a developing problem. They agree that in some circumstances, removal of cavity wall fills is the best option, but this decision must be based on evaluation and knowledge. They conclude:

“We have worked hard to promote the skills, knowledge and understanding that will be needed to inspect, diagnose and remedy the damp problems that are now being reported by homeowners, tenants and landlords across the country.”

If you’re concerned about damp and suspect it may be connected to cavity wall insulation, get in touch with Multiskill. We are a longstanding company of over 50 years experience, and members of the Property Care Association. We’d be happy to inspect your property and diagnose any problems as well as provide a solution.

Some of the information in this post was provided by the Property Care Association. Read a detailed article here or watch this helpful video which explains the problem.