Non-ACM cladding

Aluminium Composite Material (ACM) cladding consist of two skins of aluminium bonded to either side of a lightweight core of materials such as polyethylene (PE), polyurethane (PUR), profiled metal or a mineral core. It is a popular product because of its precise flatness, variety of surface finishes and colours, light weight and formability. However, during a fire, the panels can delaminate, exposing the core material.

ACM cladding became notorious following the Grenfell Tower fire on 14 June 2017, when ACM cladding with a polyethylene core was thought to have contributed to the rapid spread of the fire up the outside of the tower. Following the fire, building owners were required to remove unsafe ACM cladding from certain buildings (such as residential buildings) over 18m tall.

It subsequently emerged that there were a range of other cladding materials that could behave in a similar way in a fire. For example, High Pressure Laminate (HPL) panels, which are a form of cladding typically manufactured by layering sheets of wood or paper fibre with a resin and bonding them under heat and pressure. Remediation of this type of cladding was also required.

The term ‘non-ACM cladding’ has therefore come to refer to any unsafe cladding system that is not Aluminium Composite Material cladding.

In May 2020, the government launched a £1billion fund to meet the cost of replacing unsafe non-ACM cladding systems on residential buildings in the private and social sector that are 18 metres and over and do not comply with building regulations. Ref https://www.gov.uk/government/news/new-1-billion-building-safety-fund-to-remove-dangerous-cladding-from-high-rise-buildings

The prospectus for the fund suggested that unsafe non-ACM cladding might include: ‘…some types of other (non-Aluminium) metal composite panels, High Pressure Laminate, render and timber wall systems where these do not meet fire safety standards.’ Ref https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/887452/BSF_Non-ACM_Cladding_Prospectus.pdf

Further detail on materials within scope of the fund can be found in Annex A to the prospectus. https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/887231/Annex_A_-_technical_information.pdf

Building Safety Minister, Lord Greenhalgh said: “Now that this additional £1 billion funding is in place, building owners must crack on with removing flammable cladding on all high-rise residential buildings that are over 18 metres.”

[edit] Related articles on Designing Buildings Wiki

• ACM cladding testing by BRE.
• ACM cladding.
• BS 8414 Fire performance of external cladding systems.
• Celotex RS5000 PIR insulation.
• Cladding.
• Fire performance of external thermal insulation for walls of multistorey buildings, third edition (BR 135)
• Grenfell Tower articles.
• Grenfell Tower fire.
• Grenfell Tower Inquiry.
• HPL cladding.
• Independent review of the building regulations and fire safety.