Can Cavity Wall Insulation be Removed?

There are a few reasons why cavity wall insulation might need to be removed from a property, including damage to the walls, poor installation, or the use of dangerous urea-formaldehyde foam as an insulator. While it requires professional equipment and is a costly process, cavity wall insulation can be removed.

Is it Possible to Remove Cavity Wall Insulation?

While cavity walls offer a high level of insulation, increasing the energy efficiency of a property, there are situations where they can cease to function correctly or cause issues to your building. It is possible to remove a range of cavity wall insulation types, including mineral fibre, expanded polystyrene beads, and polyurethane foam. You can also get older urea-formaldehyde foam removed. This is a job that will require professional equipment. If the insulation within your cavity wall has been damaged, it will need to be removed.

When Might Cavity Wall Insulation Need Removal?

There are a few reasons why you may need to remove the cavity wall insulation from a house; If the house or building was unsuitable for cavity wall insulation, if the cavity wall insulation was poorly installed, in cases of fire or flood damage, or if urea-formaldehyde was used.

If a House was Unsuitable for Cavity Wall Insulation

Houses within the west of England and Scotland, and the majority of Wales are unsuitable for cavity wall insulation due to the high levels of wind-driven rain penetrating their outside walls. Reputable cavity wall insulators should not be installed within these houses, but in cases that they have, you may need to have the insulation removed. Similarly, houses with damaged outer walls or walls that are uneven are unsuited for cavity wall insulation, and the insulation may need to be removed if damage has occurred.

If Your Cavity Wall Insulation is Damaged by Fire or Flooding

Cavity wall insulation can be damaged and rendered unusable by both flooding and fire damage. If water has fully penetrated your house you will need to have your cavity wall insulation assessed afterwards. In cases of a fire within a home, even if the fire is contained, it can damage cavity wall insulation, which should be assessed. In situations where cavity wall insulation has been damaged, it will need to be removed and possibly replaced.

If Cavity Wall Insulation is Poorly Installed

Proper cavity wall insulation will result in a cavity filled with insulation material, but there are instances where things can go wrong. Alongside installations in unsuitable properties, there are instances where the installation of cavity wall fillers like polystyrene beads has been poorly done, resulting in an uneven or compromised cavity wall and leading to damp issues and cold spots. In such cases, the filling will need to be removed and replaced.

If Urea-Formaldehyde Foam Insulation Was Used

Old cavity wall insulation could pose a health risk to homeowners. Urea-formaldehyde was a foam material used as cavity wall insulation in the 70s and early 80s. It is no longer used due to the health risks it poses. Over time, urea-formaldehyde breaks down, releasing a toxic gas that poses a carcinogenic risk to those exposed. As the insulation breaks down, it will also no longer insulate the upper area of the cavity wall, causing excess heat loss. If your home is insulated with urea-formaldehyde it should be removed and replaced with a safe alternative.

How to Remove Cavity Wall Insulation

Cavity wall insulation extraction can be accomplished through a couple of methods. In the case of loose insulation, a specialist vacuum will be used to remove the insulation through drilled holes. For set insulation it will need to be broken up, which will involve removing bricks, breaking the insulation up with specialist equipment, and extracting it with a vacuum. Removed bricks and mortar will then be reinstalled.

How Much Does Cavity Wall Insulation Removal Cost?

Getting your cavity wall insulation removed will cost around £21.50 per m2 on average. While the size of houses can vary dramatically, on average covering a full house will cost about £2100. This process will take between one and three days to cover for a house. While this is expensive, removal is a specialist process, that requires equipment and training. In most cases, the cost of removal is more than the original cavity wall insulation cost.

What Are Your Options After Removing Cavity Wall Insulation?

Once your cavity wall insulation material is removed, your choices for what to do next will depend on why you removed it. If you removed your cavity wall insulation because your house was unsuited to it, you will need to use a type of insulation material that is installed to your internal wall or external wall, for which you will have several options. If you removed your cavity wall insulation due to poor installation or the use of dangerous urea-formaldehyde foam, then you can install new cavity wall insulation into your walls.