The building contained several types of combustible insulation in its external wall systems, including:
Projects of this kind often reveal hidden issues once work begins. We anticipated this and were able to manage each challenge through our detailed understanding of façade construction, external wall fire risks, and secondary construction issues that can arise during remediation.
Because the Alucobond panels held an A1 fire classification, they could be safely reused. The same applied to the glass curtain wall and the spandrel panels. We removed and stored each element with great care to avoid damage.
Once the cladding was removed, we discovered that the support gridwork included carbon fixings. These were not compliant with best practice, as stainless steel fixings should have been specified. To ensure safety, we worked with a structural engineer to complete wind load calculations, and review the required fixing centres. We also carried out pull-out tests to confirm the suitability of the substrate.
Our original intention was to use 166 mm Rockwool Hi-Impact Soffit Slab. A detailed survey showed that we needed to decrease the thickness of the product to 136mm to keep clearance from existing services. All of these changes were reviewed and approved by the architect to maintain design integrity.
To achieve the required airflow behind the rainscreen cladding, some Alucobond panels had to be modified.
For fire protection, we specified the FSI fire break system for both the cladding and brickwork areas. This allowed us to use just two product types: FSI Paraflam and FSI Silverliner OSCB. Each product type has a colour-coded wrap that identifies its rating for integrity and insulation. This simplifies installation, and reduces the chance of error on site.
Around the windows, there were no cavity barriers in the original construction. To avoid stripping back brickwork unnecessarily, we introduced additional flashings, which were approved by the fire break manufacturer.
We used our bespoke cladding remediation quality assurance system throughout the project. The building was divided into zones, and we captured detailed imagery at every stage:
FSI also inspected the installation of their products, which is a practice we actively encourage on all projects. All quality assurance data is securely stored within a dedicated data centre.
Under current regulations, this building would be classed as a High Risk Building. This work was carried out before these regulations became legally mandated. Nevertheless, we ensured that a full Golden Thread of information was created and maintained. We consider this essential to demonstrate professionalism and accountability.
We removed the panels and set them aside. The combustible insulation bonded to the glass was disposed of. We then reinstalled the retained panels with 150 mm A1-rated non-combustible duo slab insulation.
After removal and safe storage, we replaced the combustible insulation with 75 mm A1-rated non-combustible duo slab insulation. We installed new horizontal and vertical fire breaks on every floor level, and around all windows and compartments.
We removed the panels, stripped out all combustible insulation and fire breaks, and replaced them with 75 mm A1-rated Rockwool Rainscreen Duo Slab insulation. New fire breaks were installed on every floor and within the cavity behind the brickwork before the spandrel panels were reinstated.
First, all electrical services, pipework, and framing were removed. We stripped out the suspended soffit boards and combustible insulation, then installed new 136 mm A1-rated Rockwool Hi-Impact Soffit Slab and reinstated all services. New aluminium flashings were then fixed to both the brickwork and the soffit board.
This project took place during 2022/23, when the construction sector was emerging from Covid-19 and supply chain issues were common. Careful planning, efficient site management, and the intelligent use of available space enabled us to maintain productivity and avoid delays.
The building remained occupied throughout, and work had to take place around the main entrance of a busy shop. Although we now have a dedicated Resident Liaison team, at the time our site management and project planning leads took responsibility for communication with residents and store management. Their thoughtful, consistent engagement ensured that disruption was kept to a minimum.
