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March 13, 2024

How To Remove Cavity Wall Insulation & The Costs

removal of insulation (cavity wall)

Having cavity wall insulation removed can feel like a huge job. For many homeowners, cavity wall insulation might not cross their mind regularly, but when people start to think about it, it’s usually because they’re noticing some issues.

This could include anything from decreased energy efficiency in the home, increased heating bills, damp walls, and cold air circulation around the home – all of which can come on quite suddenly if your cavity wall insulation has failed.

Installing cavity wall insulation will include benefits such as reduced bills, a more comfortable home, and a reduced household carbon footprint. But to enjoy these benefits, old cavity wall insulation will need to be removed.

At Effective Home, our insulation experts can remove old and failing insulation from your cavity walls and then replace it with new, effective insulation that will bring all of the benefits you expect from having the gap between your exterior walls and internal walls filled. We’ll assess your existing insulation material and, by injecting special insulation material designed to work for your home after your old insulation removal, we’ll get your home back on track.

What Is Cavity Wall Insulation?

Every residential property throughout the UK is either built using solid walls or cavity walls. One key method you can use to determine which type of walls your house has is by analysing the brick layout.

  • Solid walls – Typically, solid walls are present in properties that have an uneven brick layout, with a mixture of brick lengths on display.
  • Cavity walls – Alternatively, even brick patterns where all the bricks in the construction have been placed lengthways are a clear sign of cavity walls. However, you may not be able to view the brick pattern of your outer wall, perhaps you have external wall insulation. In this case, simply measure the thickness of your wall, if it measures greater than 260mm, then you have cavity walls.

But what does the term cavity walls mean? Simply put, cavity walls relate to there being a gap between your internal walls and external walls. However, this gap can make your property less energy efficient as it allows cold air to circulate your property. To combat this, many homeowners install cavity wall insulation.

Types Of Cavity Wall Insulation Material

In terms of cavity insulation, there are a variety of insulation materials available on the market that you can use to fill the gap in your cavity walls. The four most common forms of insulation are:

  • Polyurethane foam (replacement for Urea formaldehyde foam insulation).
  • Polystyrene beads.
  • Mineral wool.
  • Cavity batts.

Why Would I Need To Remove Cavity Wall Insulation?

Since we have already briefly outlined the benefits of cavity wall insulation, you may be wondering for what reason people may have insulation removed. While cavity wall insulation has the predicted lifespan of the entire life of your property, that does not mean that the insulation material comes without the potential for faults. The four major reasons that homeowners may have their cavity wall insulation removed include:

Insulation Being Poorly Installed

The crux of any issue that cavity wall insulation may suffer throughout its lifetime is if you have incorrectly installed insulation. While having cavity wall insulation installed comes with a raft of benefits, if the insulation isn’t installed properly you will not receive any benefit. Instead, you may be left with issues like cold spots if your insulation doesn’t fill the whole cavity.

The main issue with cold spots is that they allow for a difference in wall temperature. The locations that don’t feature any insulation will become vulnerable to damp and mould growth. This is due to the increased risk of condensation, which can lead to damp problems. Other issues that could stem from poorly installed insulation material are lower energy efficiency, increased energy bills, and even structural damage.

Unsuitable Insulation Material Was Previously Installed

If you have old cavity wall insulation that dates back to the 1980s, then it may be time to have your insulation removed. This is because the insulation material used may cause additional health risks. Back in the 1980s, insulation installers often used urea formaldehyde foam insulation to insulate residential homes. More recently, it has been discovered that this type of insulation can release carcinogenic fumes when broken down.

If you have this type of insulation material installed on your property, then you should have the foam removed as soon as possible and replaced with one of the modern materials now available.

Failing Cavity Wall Insulation

While cavity wall insulation is expected to last the entire lifespan of your property, if the material is not installed properly, then it may not last as long. In these instances, it is more likely that you may get damaged insulation, which will lead to it failing.

Old insulation material is one of the categories most likely to suffer a failure. This could be due to a selection of reasons, including:

  • Having wet cavity wall insulation, probably due to rain penetration and wind-driven rain causing damaged insulation. A key way you will be able to determine that this has occurred is if you can smell a mouldy or damp smell in your home.
  • Perhaps over time you have developed loose insulation, which can occur when the insulation either clumps or shrinks together. This could lead to serious structural damage if the clumped insulation compromises the wall ties in your cavity walls.
  • Pest infestations. An insulation installation can provide the perfect nesting materials for certain pests like birds or rodents. If they find their way into your home, then they can tear apart, move, and use your insulation in different ways, causing potential problems for your home.

Increase Your Household’s Value

If your household has failing or damaged insulation, then there is a high likelihood that this may also negatively impact your property’s value. Those looking to purchase a comfortable or warm home will be put off by the fluctuating energy efficiency levels, with homeowners more likely to remove insulation altogether to make their homes more appealing to potential buyers.

Cavity Wall Insulation Removal Process

Now that you know some of the reasons why having cavity wall insulation removed might be necessary, it’s worth knowing how the process itself works.

Of course, individual cases can look slightly different from one another, as it may require more specialist work to access and remove your insulation based on how easy it is to access the gap between your inner and outer walls and the type of insulation material being removed, but broadly speaking, having your old cavity wall insulation removed and replaced with Effective Home will usually involve the following steps:

Step 1: Conduct A Survey

The first step to any cavity wall insulation removal is a survey. The insulation removal team will need to know exactly what the issues are, the insulation material, the problem areas, and how much insulation needs to be removed.

By working this out, a plan can be formulated to ensure no old insulation is left behind, and if you’re having new cavity wall insulation installed, a plan can be put in place for this also.

Step 2: Cavity Wall Access Point Is Created

Once a plan has been put together, the first step to removing cavity wall insulation is to create an access point by drilling a small hole in the outer wall. The hole needs to only be large enough to fit the nozzle of an industrial vacuum.

A designated area will also be set up to prevent people from coming nearby as insulation dust and debris can sometimes come loose during the extraction and proper protective gear needs to be worn to stop anyone from breathing this in.

Step 3: Insulation Material Is Removed

For the cavity wall insulation extraction, two things need to happen.

First, the insulation needs to be blown loose. The industrial vacuum needs to loosen the insulation by blowing compressed air into the cavity space.

Once the insulation is loose, the industrial vacuum collects the insulation safely. Thanks to the survey completed earlier, the removal team will know exactly where the insulation sits in the cavity wall and so will be able to ensure every last bit is removed.

Obstacles may be present like pipes, but the survey will have already picked up on this too, and the removal team will be able to work around the obstacle for a thorough removal.

Step 4: Access Point Is Sealed Up

After the cavity wall extraction is complete the hole can be sealed up again using cement. The area will then be cleaned to ensure all dust and debris are removed.

How Much Does It Cost To Remove Cavity Wall Insulation?

Removing cavity wall insulation is a straightforward enough job for professionals, but because each property is different, it’s difficult to say exactly how much it will cost.

The larger your property, the more expensive removal will be, but even some smaller properties can prove more difficult to access, meaning the removal process takes even longer, requires more specialist equipment, and costs more.

For a general guide, though, here are some industry standard estimates. When you work with Effective Home, though, prices may be more or less depending on the nature of the job:

  • Semi-detached home with three walls: £1700 to £3000 depending on the size of the property
  • Detached home with four walls: £3000 to £4300 depending on the size of the property

Can I Remove the Cavity Wall Insulation Myself?

No. Not only will you not have the necessary training that cavity wall extraction teams have, but you also won’t have the equipment. Industrial vacuums are not like the vacuums we have at home, so you wouldn’t be able to successfully remove the insulation even if you wanted to.

The cost of removing insulation may be off-putting, but the savings you’ll make by renewing your insulation will eventually cover the cost, so don’t try to cut corners by doing the job yourself – this can lead to unsuccessful removal, and that can cause more issues in the long term.

How Long Does Cavity Wall Insulation Removal Take?

Provided the survey and removal process is relatively smooth, most removals will only take between 1 and 3 days to complete, with a shorter removal time being associated with smaller properties.

In some rarer cases, it may take longer, but this will be due to especially difficult extractions caused by obstructions and much larger properties.

How To Remove Cavity Wall Insulation & The Costs Summary

Hopefully today you’ve been able to see that removing cavity wall insulation is a simple process for those with the right training and equipment. It’s also worth noting that removing insulation is necessary in some cases to protect your home from potential issues such as damp problems or structural issues.

The costs of cavity wall insulation removal can seem quite high, but by replacing old insulation with new, you’ll enjoy a much more energy-efficient home once again, and this will result in higher energy bill savings that will eventually cover the cost.

If you’re looking for new cavity wall insulation then enter your postcode today for a free no-obligation quote.

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Justine Effective
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