top of page


All cavities are cleared of “old” insulation and debris, inspected and certified as being completely clear. Only when completely clear can the cavity be filled again.  

Why should I replace existing insulation?


Older insulation materials such as Urea Formaldehyde, Mineral & Glass Fibre tend to break down over time or can get saturated with moisture, with brick and mortar being of a porous nature, moisture can penetrate into the insulation material. If the insulation gets damp, with little air circulation the damp can become saturated, and the insulation material soon becomes a heat inhibitor rather than an insulator.  This damp  can then penetrate into the inside wall causing darkened damp spots, crumbling plaster or fungal decay.  If not dealt with this could lead to structural damage.


Similarly, poorly or incorrectly installed insulation material, may cause voids in the insulation causing cold spots in large areas of outer walls.

How is the extraction done?

The redundant cavity wall insulation is removed using an industrial vacuum machine. A recognised approved drill pattern, similar to that for cavity filling, is drilled. Using compressed air, the old insulation material is directed towards the vacuum and extracted.

The removal of insulation material and possible debris starts at the base of the property, working its way up each wall according to the drill pattern, checking with a borescope that the entire cavity wall is free from insulation and debris.  All waste material is bagged and taken away during the extraction. Once completed, a Certificate of Clean can be issued and the filling process can commence.


The cavity wall extraction and fill process can take two days to complete in an average three-bedroom detached property. We are not allowed to top up insulation. All gaps and voids must be fully extracted before installation of our insulation can be carried out.


All of our cavity extraction teams are trained to the highest standards, and adhere to BBA Cavity Extraction guidelines.

Extraction and refill cavity wall insulation
Extraction - Cavity Wall Insulation
bottom of page