Allan Jowsey and John Dunk, Directors at PFP Specialists Ltd on the importance of demonstrating fire protection capability in older buildings
PFP or Passive Fire Protection products and materials are installed in structures to provide fire protection in the event of a fire. In recent months PFP Specialists has been contacted by concerned building owners and operators, regarding increased requirements to understand the fire safety capability of buildings, given recent and pending changes in regulation.
In newer buildings this is most likely documented ‘as built’ evidence of the fire protection measures in place. However, in older buildings or buildings with structural modifications, it is not always possible to find substantiated record of the passive fire protection originally installed.
Passive fire protection in this context could include boarding, intumescent coatings or cementitious coatings applied to steelwork, or in some cases, to reinforced concrete structures.
REGULATORY CONTEXT AND IMPLICATIONS
The Grenfell Tower fire of 2017 was a tragedy that resulted in many calls for increased fire safety in buildings and for the UK’s Building Safety system to be reformed.
Proposed changes to the regulatory requirements were published by the government in July 2020 by way of the Building Safety Bill.
Changes in legislation will mean greater emphasis on the building safety management process and there will be a Building Safety Manager identified to be responsible for this and other aspects.
UNDERSTANDING FIRE RESISTANCE
A fire safety strategy for a building will typically set out the fire resistance requirements that must be achieved. In many cases, this is typically referenced as a fire resistance period, e.g., 60-minutes, 90-minutes, etc.
In new construction and recently constructed buildings it is most likely that the passive fire protection methods put in place will have been documented in design, specification, and construction, so it is reasonably easy to identify the various measures used to provide necessary protection.
Recently though, there has been an increase in interest by building owners and developers, specifically in older structures, to ascertain the current level of fire resistance, where there is no documentation available as to what was originally installed to protect the structure.
This situation is obviously of major concern to building owners and managers, as not being able to identify fire protection materials applied to structures means there can be no proof of fire protection capability, and therefore structural fire resistance performance. This can carry risks associated with satisfying the approving authority and potentially the compliance, from an insurance perspective. Where structural fire resistance cannot be adequately determined, a remedial action may involve stripping out of what is there and reinstatement with a known product. Clearly the logistical and commercial implications here are vast.
SITE SURVEYS AND INSPECTIONS
A Fire Risk Assessment may identify further investigation is required relative to the applied passive fire protection systems, but in most cases, specialist fire protection professionals may need to be consulted to conduct further inspections.
In the case of existing installations, where there is no record of the product applied or its fire resisting capability, there are processes that can adopted:
- General visual inspection: on-site surveys of installed product and by visual inspection to identify the generic type of the passive fire protection material
- Close visual inspection: On-site condition survey including thickness measurements and overall integrity
- Laboratory analysis: Removal of samples from site for investigations including spectroscopy and thermal conductivity measurements
A key objective is identifying the passive fire protection product’s manufacturer and product name. With this information, a review of the material’s original fire resisting capability can be made to determine if it will provide the required level of protection. This could involve reference to the product’s datasheets and performance declarations.
In-situ thickness measurements also provide insight since these can be correlated against published thickness tables for products to quantify fire resistance capability.
The passive fire protection industry can move at a fast pace. In certain circumstances, products may have been superseded and no longer produced. Manufacturers may have gone out of business or may have been bought out by other suppliers and their products integrated into a larger product offering, with potential rebranding. Trying to find pertinent documents for suspected products can potentially be challenging for older structures. Dialogue with industry professionals and direct contact with manufacturers is often required as a part of a detective activity.
Laboratory analysis provides very useful assessments to help identify fire resisting capability of a material. Small samples can be removed from site for consideration and analysis can be used to determine the generic type of product installed and further properties to develop a profile of the material. This profile can then be used to identify the specific product by manufacturer and type.
Combinations of site inspections, lab testing of samples, and specialist industry and product knowledge is typically required to make an informed evaluation.