Page 46

RCI December 2017

CLADDING & SHEETING “Insure to ensure” 044 DECEMBER 2017 RCIMAG.COM By Mark Harris, divisional building technology director at Kingspan Insulated Panels Fire within buildings is a complex phenomenon. Numerous factors contribute to how it progresses and behaves. In building envelopes, the fire performance of the system is dependent on the interaction between all component parts, including fixings, fasteners and sealants. Additionally, the way the system is designed and installed can have a significant effect on how it reacts to fire. It is crucial therefore, that whole systems are tested, rather than relying on small scale tests on individual product samples and potentially ignoring the fire performance of some components. To provide clearer assurance of performance, a growing number of envelope products are seeking approval under insurer standard schemes from bodies such as the LPCB (Loss Prevention Certification Board), and FM Approvals. These standards use a variety of assessments, including full scale tests of the system as it will actually be installed, to ensure the installed system will provide the expected fire performance. A sure deal The insurance industry has a vested interest in loss prevention, both protection of life and property. Since the early 1990s, it has developed its own set of large-scale system tests to ensure a more accurate risk assessment can be made of specific building constructions. Whilst the Building Regulations are primarily focused on ensuring occupants can safely exit a building in the event of a fire, insurer approval schemes have been designed to determine how well the building fabric will continue to resist fire spread after occupants have been to preserve valuable property assets. Over the years, case studies by independent experts have shown that there is a very close correlation between the results of insurance industry large-scale testing and actual building performance in real fires The two most widely-recognised insurer standards for the fire performance of building envelope systems in the industry are LPS 1181 from the LPCB and FM 4880/4881 from FM Approvals. LPS 1181 Part 1 – A brief overview LPCB’s LPS 1181 Part 1 assesses the performance of roof and wall systems through a large-scale test. The test is designed to measure fire spread, and is suitable for a range of building types. The complete system is installed within a 10m long x 4.5m wide x 3m high enclosure with an open front and ventilation window at the side. A large wooden crib is located on a steel table inside. One of the key performance requirements is that there shall be no sustained surface flaming beyond 1.5m from the perimeter of the crib in both horizontal directions on the walls and the ceiling. In addition, there are specific pass / fail criteria related to flashover, external surface flaming, burning brands from the ceiling, concealed burning and damage. FM 4880 and FM 4881– A brief overview FM Approvals is an internationally recognised third-party testing and certification service as part of FM Global, a worldwide insurance company that specialises in loss prevention. To achieve FM 4880 Class 1 Internal wall and ceiling panels without height restriction and FM 4881 Class 1 External wall panel systems without height restriction, products need to not only demonstrate that they do not propagate fire in a range of tests including small-scale material flammability tests and larger scale system tests which can include a 50ft corner test to establish the performance of insulated panel systems. The panels in these largescale fire tests are installed in quantities and applications which replicate how they would be used in everyday field constructions. The results are then analysed to provide recommendations on limitations to the final application for which the wall and ceiling materials are FM Approved. It is extremely important to note that both the LPS and FM tests detailed above are designed to assess the performance of specific systems in a fire, including the fixings and joints. The data provided is only relevant for the system tested and can’t be used to approve similar build ups with alternative materials. Insulated Panel Systems – case studies Metal-faced insulated panels with rigid PIR cores are one of the most popular wall and roof system solutions in the UK and these systems can meet the rigorous testing of the insurance industry fire performance standards. Independently researched fire case studies have proven the performance of insurer certified PIR panel systems across the world, in different applications and different firerelated incidents. One UK example is a fire which occurred at Wharfedale Hospital in Leeds in 2003 whilst it was under construction. The building was steel framed with concrete floors. The first and second floors had been covered with Kingspan PIR insulated panels approved by LPCB to EXT-B of LPS 1181 Part 1, however, the ground floor panels had not yet been installed and it was left open sided. It is thought the fire was started deliberately by adhesive which had been stored on the ground floor. The fire was discovered by onsite security, who alerted the fire service who brought the fire under control within 40 minutes. The heat generated by the fire was significant. The concrete floor cracked and the steel beams, which had been protected with a fire-resistant intumescent coating, distorted. The fire service found light smoke but no fire spread on the upper floors of the building. The independent report concluded that the PIR core of the insulated wall panels did not promote fire spread. A series of 15 real fire case studies in a range of occupancy types has given similar conclusions demonstrating that PIR cores char; fire is not propagated within the core and there is no evidence to demonstrate that insurance industry approved panels increased the risk of fire spread. Benchmark for safety Opting to use insurer approved products is beneficial in a number of ways. In addition to making the insurance process much simpler, the rigorous realistic nature of the large-scale tests offer increased peace of mind that the product will perform as expected in a fire situation, reducing the risk of loss of property www.kingspan.com “To provide clearer assurance of performance, a growing number of envelope products are seeking approval under insurer standard schemes” An independent report concluded that the PIR core of the LPS-tested Kingspan Insulated Wall Panels did not promote fire spread during an incident at Wharfedale Hospital in Leeds


RCI December 2017
To see the actual publication please follow the link above