Specialist Extraction of Cavity Wall Insulation
Why Might it be Necessary to Remove Cavity Wall Insulation?
It is estimated that over 6 million properties around the UK have had cavity wall insulation installed, however we live on an island with a generally damp climate often exposed to high winds and even icy conditions. Such a climate can take its toll on brick work and can lead to gaps opening up in bricks or pointing and water getting into the cavity itself. The purpose of insulation is to limit air flow and increase thermal value. The problem with fibre or foam is that once it becomes wet, it is virtually impossible to dry out without causing other issues in the property such as efflorescence and damp spots on the inner leaf.
Dampness is typically caused by poorly maintained exterior brick work, severe and constant exposure to wind and rain or incorrectly installed cavity wall insulation products.
Increasingly wet winters have resulted in an increase in the reporting of damp issues in properties with cavity wall insulation, particularly those insulated with fibrous or foam based materials which do not allow the dispersion of moisture. A likely cause of damp penetration at these levels is the bridging of the cavity by the insulation product. Moisture penetrates into the cavities more noticeably on weather prevailing walls and as the insulation material becomes saturated it will inevitably result in dampness showing on the internal walls.
Not all properties are suitable for Cavity wall insulation and extraction may be necessary for a number of reasons, including:
- The property is exposed to wind driven rain, which can penetrate the outer leaf of brickwork causing rain water to enter the cavity.
- Porous brickwork or mortar.
- Defective external render.
- Defective Wall ties.
- Flooding / Burst pipework can cause cavity insulation to become wet.
- Dirty cavities from debris falling down the cavity during its construction or dust settlement over a period of time.
- Defective insulation material (such as Urea-Formaldehyde) can break down and release toxic gasses.
- Early foam insulation was not covered by the same stringent BBA certification licences as modern materials.
- Incorrectly installed insulation, through incorrectly located drill pattern or through not carrying out a fill test to determine the correct fill rate, leading to voids within the cavity These can then cause cold spots within the cavity, leading to condensation and damp problems.
- Poor installation practices such as neglecting to take account of cavity wall and sub-floor vents, designed to help the building breathe and stay dry.
It is important to note that the property may have been suitable for the insulation at the time of install but the effect of time and weather can cause any or all of the above issues.
The cavity extraction process
The redundant or defective Cavity Wall Insulation is removed by blowing compressed air into the cavity while an industrial vacuum machine collects the waste insulation from the bottom of the wall through strategically removed bricks.
The removal of material commences at the base of the property, working its way up the drilling pattern checking that the entire cavity wall is free from insulation material. All waste material is bagged during the extraction process and all waste materials are removed from site for safe disposal. Before leaving your property, in accordance with our Customer Care Policy our staff ensure that any remedial work is completed to your satisfaction and your property is left clean and tidy – exactly as we found it.
The Cavity Wall Insulation Extraction process can take up to 2 days to complete for an average three-bedroom semi-detached property. Following the extraction of the redundant/defective insulation the cavity void is inspected and photographed using a borescope to ensure the cavity insulation is completely removed.
Materials that can be extracted
Below is a list of materials that can be extracted from cavity walls:
- Loose and/or bonded expanded polystyrene
- Urea Formaldehyde Insulation
- Rockwool Mineral Fibre
- Whitewool Glass Mineral Fibre
Replacing the Insulation – Refilling your cavity
So now, you have had your defective cavity wall insulation removed, don’t forget, Arktek Group is a leading installer of injected blown bead insulation systems. Arktek work with Thermabead – industry leaders in the supply of bead insulation, offering high performance, outstanding durability, water resistant and rot proof our bead product is the number one choice for insulation.
Our cavity wall extraction teams are all directly employed and trained to the highest standards, and adhere to strict BBA guidelines. Is addition to all of our accreditations as a Green Deal Installer, we are also accredited by Stroma an industry required certification to ensure that Cavity Wall Extraction (CWE) is completed to the highest standards.