One of the major considerations, if not the main consideration, when choosing an external wall insulation system for refurbishment over-cladding of an existing building façade, must be the fire performance of the chosen EWI system.
Fig1. External Wall Insulation Cladding Fire
The specifier should ensure that the chosen external wall insulation system is suitable for use:
and must strictly comply and be carried out using an appropriate external wall insulation system incorporating system materials and components, design and installation procedures which are the subject of a current valid independent third party UKAS accredited certification.
and the installation must be strictly in accordance with the Certification requirements, Building Regulations (fire safety, and materials and workmanship) and any other regulations that relate to the installation of the measure.
I-CAN staff has over three and a half decades of research, testing and assessment of external wall insulation systems experience and was the Project leader for the Department of Trade & Industry (Dti) Partners In Technology Project (PiT), Multi-Storey Fire Tests on External Wall Insulation (EWI) Cladding Systems in March 1997.
Fig2. External Wall Insulation Cladding Multi-Storey Fire Test
The primary aim of these tests was to evaluate the fire spread over the external surface of the insulation system façade, fire propagation and spread within the system, and the mechanical response of the external wall insulation system such as distortion and collapse. The effectiveness of horizontal fire barriers was also studied.
In the event of a fire, the external wall insulation cladding system must prevent fire from spreading rapidly across a building’s facade, or leap-frogging from window-to-window, to allow people time to escape from the building.
The design of all horizontal and vertical fire-breaks in existing installed external wall insulation systems is critical and checks should be conducted to ensure the specification and installation strictly and precisely followed that of the external wall insulation system and fire-breaks that had been tested.
I-CAN staff has been involved in assisting Local Authorities and Registered Social Landlords in carrying out inspections of fire damage to existing external wall insulation systems on multi-storey buildings and advising on the remedial works required to make good fire damage.
If you require assistance in carrying out inspections of existing external wall insulation systems on multi-storey buildings please click here to contact us.