Charrington Court, High-rise Residential Building

Project overview

Charrington Court is a high-rise residential building that underwent a comprehensive façade remediation programme to address fire safety concerns and bring the external envelope in line with current regulatory expectations. The project was initiated following inspection findings that identified discrepancies between the as-built façade materials and the original design intent.

The remediation works focused on replacing combustible elements with a fully compliant non-combustible façade system while maintaining the building’s existing appearance and thermal performance.

The challenge

The project presented a number of technical and operational challenges:

• Replacement of combustible façade materials on an occupied high-rise building
• A requirement to retain the existing architectural appearance and colour palette
• Multiple substrate types, including steel frame and masonry construction
• Uneven existing substrates requiring façade levelling
• Restricted site footprint limiting storage and material handling
• The need for extensive resident engagement throughout the works

In addition, the client required the remediated façade to achieve an A2-rated system while maintaining a target U-value of 0.18 W/(m²K).

The solution

A Wetherby cavity rail external wall insulation system was specified to meet the fire, thermal and aesthetic requirements of the project. The system incorporated a drained cavity between the insulation and the substrate, providing enhanced moisture management and suitability for high-rise construction.

The façade build-up included non-combustible ROCKWOOL stone wool insulation fixed to Wetherby Ragrails, creating a cavity zone before the application of the decorative finishes. This configuration allowed the system to accommodate substrate irregularities while delivering consistent thermal performance and fire resilience.

Both brick slip and silicone render finishes were used to replicate the original façade appearance, ensuring continuity with the surrounding urban context.

Installation

The EWI system was installed by MK Facades, a Wetherby-recognised contractor with extensive experience in complex remediation projects. United Living acted as main contractor, coordinating the multi-disciplinary works.

Prior to installation, Wetherby carried out pull-out testing across multiple elevations and heights to verify fixing performance. Wind load calculations were also undertaken to determine the appropriate fixing specification and spacing, ensuring compliance with project-specific structural requirements.

In areas where the existing substrate was uneven, a double-boarding approach was adopted to level the façade before the application of the finishing layers.

Finishes and detailing

The primary render finish was a silicone thin-coat system with integrated anti-crack properties and UV-resistant pigments, enhancing long-term durability and colour stability. Alkali-resistant reinforcing mesh was incorporated into the basecoat to provide additional strength in high-stress areas.

The combination of rendered and brick slip finishes allowed the system to closely match the original façade design while upgrading its fire and thermal performance.

The result

The completed remediation works delivered a fully non-combustible external wall system with an achieved U-value of 0.18 W/(m²K), meeting both the client’s thermal targets and current fire safety expectations.

The cavity rail system provides long-term moisture management, improved durability and enhanced fire performance, ensuring the building’s façade is compliant, resilient and fit for continued residential use.

Key facts

• System: Cavity rail external wall insulation system
• Substrates: Steel frame and masonry
• Insulation: Non-combustible stone wool
• Finish: Silicone render and brick slips
• Fire performance: A2-rated system
• Achieved U-value: 0.18 W/(m²K)