This EWI remediation case study details how our team rescued a Coventry family from a dangerous and abandoned external wall insulation project.
* Location: Coventry
* Property Type: Tin house / System-Built Property
* Project Type: Failed Contractor Rectification & Full EWI Remediation
1. Executive Summary
This case study details a critical intervention by our team to rescue a Coventry family from a highly dangerous and fraudulent exterior wall insulation (EWI) project. The homeowners had previously paid a rogue contractor nearly £10,000, only for the builder to apply a substandard basecoat, abandon the site completely, and block the customer’s phone number.
Following a recommendation from neighbours who trusted our workmanship, the client contacted us to inspect the property and provide a path forward.
2. Photographic Evidence & Inspection Findings
Our team conducted a comprehensive diagnostic survey of the property’s exterior. Photographic documentation captured a series of structural failures and critical safety violations:
Structural & Material Failures
Substandard Substrates: Instead of approved, industry-standard EWI insulation panels (such as EPS, Mineral Wool etc), the previous contractor had simply mechanically fixed OSB directly onto the property’s timber-frame elevations.
Severe Bowing & Cavities: Photographic side-profiles revealed massive, uneven bulges across the elevations. Huge gaps were left between the OSB boarding and the actual face of the walls. This created an unsealed “chimney effect” cavity, severely compromising the thermal performance and creating an extreme fire propagation risk.
Incorrect, Corroding Mesh: Rather than using the BBA approved mesh for EWI systems, the contractor utilised an indoor-grade metal mesh. As captured in our close-up window inspections, this mesh was completely unsealed, exposed to moisture, and already heavily rusted and oxidising. This rapid corrosion caused deep stress cracks to ripple across the entire yellow basecoat.
Critical “Risk to Life” Safety Hazard
Obstructed Boiler Flue: Most alarmingly, our inspection discovered that the contractor had rendered directly up to and partially covered the property’s boiler flue. By restricting the exhaust, the contractor trapped toxic emissions, exposing the clients and their small children to an immediate, lethal risk of Carbon Monoxide (CO) poisoning.
As soon this hazard was discovered, the emergency services were notified who immediately rectified the problem. Unfortunately, and due to the urgency of the matter, it is understandable why we did not take a picture of the boiler flue in its hazardous state. We do, however, have a picture of the boiler flue after it was uncovered and extended.
3. The Remediation Strategy
Because the foundation of the previous installation was entirely compromised and the wrong materials were used, no elements could be left on the property. Leaving the OSB and rusted mesh in place would trap moisture and it would lead to other issues as well.
Our team executed a complete removal after ensuring the immediate risks were mitigated, validating proper ventilation and airflow to safeguard the family.
Total Deconstruction: Stripped away 100% of the failed yellow basecoat, rusted metal mesh, and unapproved OSB boarding, exposing the original structure.
Regulated EWI Installation: Fitted a fully compliant, high-performance external wall insulation system using correct insulation boards, premium basecoat, and specialised mechanical fixings.
Weatherproof Finishing: Applied an advanced thin-coat silicone render system to guarantee long-term flexibility, breathability, and a crack-free finish.
4. Final Outcome
The completed EWI remediation restored the property’s safety, energy efficiency and external appearance.
While the homeowners faced an incredibly stressful and financially damaging ordeal at the hands of an unregulated builder, our team successfully transformed a hazardous shell back into a safe, energy-efficient, and beautiful home.
By adhering strictly to UK building regulations and manufacturer specifications, we gave this family total peace of mind, restored their property value, and proved the vital importance of hiring trusted, recommended professionals.
