Cavity wall extraction process?

Cavity Wall insulation coming out of a vent

We carry out full extraction investigations and re-installations for homeowners in the UK who are suffering the consequences of poorly installed cavity wall insulation. The idea is that if the various investigations recommend full cavity wall insulation removal and re-installation, then we are best placed to help you restore your property to its former glory but free from all these problems in the future.

I have a problem with my cavity wall insulation – what should I do as a first step?

If you were to call us today, we would advise you on some of the preliminary searches on the property, which includes the following elements:

  • Checking whether your property cavity wall installation is backed up by the Cavity Insulation Guarantee Agency (CIGA) guarantee;
  • Any other relevant searches on the property using our desktop software.

The initial CIGA check is absolutely critical because it is the industry wide warranty that is usually issued to the property owners by installers after they had the cavity wall insulation installed (approx 6m homes are covered under this scheme). If the property installation is covered by the CIGA warranty then there is a possibility that the cavity wall insulation may be removed free of charge, if CIGA can determine that there was an installation fault with the initial install.

Here at Extraction4Homes we are more than happy to lead the customer right through the process as we have the appropriate contacts in CIGA to help fast track any claims. This is always our first check in the process.

What happens next if there is a valid CIGA guarantee?

CIGA at this point will do their own due diligence and contact the installation company who carried out the original install. If the company no longer exists they will ask another company to carry out the checks on their behalf.

Once the checks have taken place, CIGA will determine whether there was an installation error or it is the customer’s fault through improper use of their property.

The CIGA option is not successful – what can I do?

If the CIGA option is unsuccessful, we will use our network of trusted removal companies to quote and remove the insulation. The cost of getting cavity wall insulation removed is £21 – £22 / m2 depending on the material that was used in the first place, therefore for a semi-detached (which is 80m2) the price will be approximately £1,680 + VAT @ 20%. For a bigger detached property (so roughly 120m2) the price to remove the cavity wall insulation would be a £2,520 + VAT @ 20%.

Obviously, if the CIGA guarantee does allow us to get the insulation removed then that will be the end of the process. If the CIGA guarantee doesn’t work then we will send out an indication of cost for the works based on the prices quoted above and obviously there is no commitment on your side to follow through if the price is too expensive!

Full survey and quote for cavity wall insulation removal

We may ask for photographs of the property to provide us the initial overview of your query. If you are happy with our indication of costs for the works, we will send out a fully qualified cavity wall surveyor to carry out a fully survey. The full survey will itemised the full schedule of works proposed to help restore your property to its former condition.

Please note the cavity wall extraction survey may flag to use other remedial works needed in addition to the removal of the insulation. The following additional works may need to take place:

  • Treatment of the base profile or the DPC of the property;
  • Re-pointing the brick work;
  • Installation of adequate ventilation;
  • Repairs to the external services – guttering, downpipes, facia boards and waste pipes;
  • Removal of existing render (in some circumstances).

Cavity wall extraction process

The cavity wall extraction process involves taking out the brickworks to expose the insulation in the cavity and simply sucking it out with an industrial sized hoover, which is approved specifically for these works.

The process of sucking out or removing the insulation may take up to day, depending on access issues and the size of the property. Insulation should be removed out of the whole cavity even below the DPC (if any cavity wall insulation is present).

Cleaning out the cavity & carrying out the remedial works

As discussed in the previous section remedial works may need to be carried in addition to the extraction process. For example if the DPC layer has been breached, this may be causing rising damp issues. Here we would recommend treating the DPC layer and ensuring the damp wall/s dry out properly before the cavity re-insulated.

The cavity needs to be cleaned properly and check for any additional debris. Sometimes cavity wall insulation problems may arise due to this precise reason – where the cavity wasn’t inspected for debris properly and the insulation went in regardless.

Re-insulating the cavity with appropriate materials as an option

At this point the cavity should be cleaned and clear from the problems you have been experiencing. We would give you the option of having it re-insulated properly using our network of approved partners.

Depending on what type of cavity walls you have we will determine the appropriate re-insulation material to make sure the install doesn’t have future problems – should you go down the re-insulation route.

Thin coat render or external wall cladding as an option

We have partnered up with EWI Pro Insulation Systems, who are a BBA accredited external wall insulation and render facade manufacturer. If your walls are particularly exposed to the elements you may want to re-insulate your cavities and have the outer skin rendered using the EWI Pro approved products (using their network of qualified installers).

Alternatively if you don’t like the principle of cavity wall insulation you could have the external skin cladded with either 50mm or 90mm of cladding insulation material, finished off with the thin coat render.

Insulating or rendering will prevent damp from outside entering into the property. It will protect your property from external weathering elements affecting the inside of your home.

Final thoughts on cavity wall extraction

Our expertise is the diagnostics of poorly installed cavity wall insulation and then helping the customer proceed from the beginning of the process right till the end until the problems have been resolved.

When the cavity wall insulation has been removed we can also help with critical remedial works as well as suggesting options the customer could also go with in addition to help future proof the property from these problems occurring again.