The LWF Blog

Fire Engineering for Healthcare Premises – Structural Fire Protection – Part 18

January 18, 2021 12:41 pm

In LWF’s blog series for healthcare professionals, our aim is to give information on best practice of fire safety in hospitals and other healthcare premises. In part 17 of Fire Engineering for Healthcare Premises, LWF discussed smoke spread and control in healthcare environments through depressurisation and hot-smoke tests. In part 18, we will look at the provision of structural fire protection.

Structural fire protection measures (also known as passive fire protection measures) are those fire precautions which are built into the fabric of a building to avoid the spread of fire from one area to the next or from one building to the next. In contrast, active fire protection measures are those fire precautions which are added post-build and respond to instances of fire, one example would be a fire alarm system.

Structural or passive fire protection products used are classified by fire-resistance time – this is the time in minutes which they will withstand fire and smoke for. Commonly, they are given 30, 60 or 90 minute fire-resistance ratings.

Fire-resisting performance in a standard test and performance in a real fire can have very different results and, as such, fire-resistance time ratings cannot be construed as how long a structure will last in a real fire situation. The fire-resistance ratings can, however, be used as a measure to compare the performance of different designs.

The failure mechanisms of elements of the building’s structure must be considered. Particular consideration should be given to the failure mode and any trigger points or performance limits. If and when the element fails, is it likely to be catastrophic and without warning, or progressive and gradual?

The difference between a total and catastrophic failure and a progressive, slower failure can be, in practical terms, the difference between a successful evacuation of patients and staff and a disaster.

When considering fire severity, the potential must be compared with the fire resistance of the structure, in terms of time in minutes, temperature or load-bearing capacity to ensure a suitable safety margin can be demonstrated.

Where fire severity is expressed in terms of equivalent exposure to a standard fire, in order that fire-resistance can be extrapolated from fire test results, it may not be valid for some structures.

In Part 19 of LWF’s blog series, LWF will look at time-temperature curves. In the meantime, if you have any questions about this blog, or wish to discuss your own project with one of our fire engineers, please contact us.

Lawrence Webster Forrest has been working with their clients for over 25 years to produce innovative and exciting building projects. If you would like further information on how LWF and fire strategies could assist you, please contact LWF on freephone 0800 410 1130.

While care has been taken to ensure that information contained in LWF’s publications is true and correct at the time of publication, changes in circumstances after the time of publication may impact on the accuracy of this information.