Why might I need to have my cavity wall insulation removed?

When the right material is correctly installed, cavity wall insulation will help your home stay warm, safe and energy efficient.

However, cavity wall insulation can cause penetrating damp, mould and condensation if:

  • It’s old and worn
  • It was installed incorrectly
  • Your home is in a high exposure area. (Find out if yours is)
  • The cavity was not clear before the insulation was installed
  • The structure of your home is not suitable for cavity wall insulation
  • You have damaged walls such as cracks in the brickwork, render or pointing
  • Blockages have entered the cavity because of building works or home improvements


  • Gaps in the insulation allow heat to escape and damp to penetrate
  • If the insulation gets wet it will act as a sponge, drawing water across and holding it against your walls
  • The insulation can prevent adequate ventilation and cause damage to, for example, a steel frame, suspended wooden floors and wall ties

It may take a few years before you notice anything but damp could still be damaging your walls before it becomes obvious. It’s likely your energy costs will be rising too, as your heating will have to work harder to maintain a comfortable temperature.

(This also applies to loft insulation. If you’re concerned about yours we have more information here.)

If you think your cavity wall insulation may be damaging your home we can help. We can:

  • 1.

    Carry out a heat loss survey to see if your cavity wall insulation is damaging your home
  • 2.

    Advise you on how any problems we find can be resolved
  • 3.

    Remove problem cavity wall insulation
  • 4.

    Completely clear every elevation of any other materials or blockages (see more about our cavity wall cleaning)

How we remove your cavity wall insulation

One of our Directors Gary Randle developed the system that we use to remove your cavity wall insulation, which is in common use across the industry. The BBA originally approved this process in 2009, reapproving it in 2015.

  1. We undertake a thorough survey of your home, including the condition of your external and internal walls and any existing areas of damp. We can then let you know how much it will cost to clear your cavities.
  2. We prepare the site and erect scaffolding if necessary.
  3. We create 5 – 10 openings at damp proof level in the external wall by removing bricks at predetermined distances.
  4. We fix specially designed extraction covers to the openings and attach an extractor.
  5. We drill a series of holes in the mortar line or render and use air pressure to force the insulation materials down to the extractor.
  6. We inspect the cavity at regular intervals throughout the extraction using a 360o video boroscope that gives us a 2m view in every direction.
  7. When the extraction is complete and we’ve confirmed all the cavities are completely clear we reinstate the walls and return your home to its original state.
  8. We clear and clean the site.
  9. We carry out a final inspection of your property.
  10. Our technician fills out and signs a completion certificate, which we ask you to sign as well.

If you have a dispute about a previous installation of cavity wall insulation that you think may be causing damp in your home

call us on freephone

0800 292 2554

Cavity wall insulation can be good for your home

As long as the right material is correctly installed and your property is well-maintained, cavity wall insulation will help keep your home warm and cut your energy bills. Once your cavities are clear, and if the structure of your home is suitable, we can install cavity wall insulation that is guaranteed to protect your home.