London & Quadrant Housing Trust
Replacement Cladding at Westside Apartments
Faithorn Farrell Timms were appointed by London & Quadrant (L&Q) in February 2018 to project manage the removal of the ACM cladding, and associated assembly including carrier rails and cavity barriers, at Westside Apartments and the replacement with a new assembly incorporating A1 and A2 class materials. The main contractors were AD Construction. Westside Apartments, built approximately 13 years ago, is a 5-storey timber frame aluminium and brick clad residential dwelling in Ilford, London.
Our role was to act as the main consultant lead, contract administrator, quantity surveyor, technical inspector and principal designer. We discussed our proposals with all stakeholders, including the Planning Authority, where planning permission was not required as panels were replaced on a like-for-like basis but with aluminium material. We consulted with residents, the local authority and our client.
We developed a design for replacement with the main contractor and our client to agree the best way forward with a bespoke replacement cladding system. L&Q directly appointed a fire engineer to sign off the proposals. FFT undertook weekly inspections and reports
We also accompanied building control on their visits. Building Control was managed via independent building inspectors and managed through FFT.
A major challenge was to determine a system that would provide the right fire protection and comply with building regulations (ADB), and then apply that to an existing timber frame building and ensure that the works were undertaken in a systematic fashion. The residents were in occupation and thus the methodology and approach had to be carefully assessed with a full risk map being developed to support the project.
We aided in designing the scaffolding and ensuring that we had fire rated/retardant sheeting during the stripping phase, which also provided security, safety and weather protection throughout the works.
A further factor was the new imposed dead and wind loads through the design onto the existing structure. We engaged our structural engineers who produced calculations to demonstrate that the proposals were acceptable, which also incorporated undertaking trail pits to determine the suitability of existing foundation design.
We jointly developed a ‘Rock-Panel’ system, in which we applied an A1 rated non-combustible flexible sheathing board (calcium silicate-based fibre cement building board), fixed to the existing sterling board.
We applied the A1 fire rated cement particle boards over the sheathing board, all of which was mechanically fixed. We used A1 fire rated rockwool duo slab insulation and mechanically fixed these through the new assembly, picking up timber studs where we could, however also through the new assembly created.
The carrier rails were fixed through the new assembly to carry the new rock-panels. The design included new vertical and horizontal fire cavity barriers in accordance with Building Regulations and to a higher standard, insofar as we compartmentalised more sections than the approved document recommends. Every section of the works was inspected by FFT, the fire engineers and building control. A full quality assurance system was instigated to full audit every assembly layer.
The Rock panel system chosen matched the metallic ACM panels removed.
We also undertook measured surveys and set out a grid of each elevation to match the existing, therefore, satisfying the planners and clients alike.
Where there were areas of detailing, around the windows and doors, we applied an EDPM rubber membrane to ensure that the immediate area was watertight.
The clients leaseholders were not charged for the works for this project.