The LWF Blog
Fire Risk Assessment for Healthcare Premises – Managing Fire Safety – Part 116December 5, 2022 12:03 pm
LWF’s blog series for healthcare professionals aims to give information on best practice of fire safety in hospitals and other healthcare premises. In part 115 of Fire Risk Assessments for Healthcare Premises, LWF talked about compartmentation and the requirements for healthcare buildings. In part 116, we will continue discussing compartmentation in healthcare buildings.
As outlined in the last blog in this series, compartmentation is the process of constructing a building with fire-resisting materials to ensure fire cannot enter or spread from a compartment into the next within a given time frame, usually 60 minutes in healthcare buildings. In addition to fire-resistant, walls, floors, ceilings, doorways and doors, other openings into the compartment must be protected too.
An opening comprising a protected shaft or stairway between compartments should form a complete barrier to fire between different compartments to which the shaft connects. In the case of stairways and lifts between floors, this is usually achieved through the use of protected lobbies.
The combined fire resistance of the two sets of doors or doorsets to the lobby should be at least 60 minutes. Two doors are necessary to ensure products from a fire cannot enter the protected lobby.
Protected shafts should have a means of ventilation. For a protected shaft containing a stairway, at the top of the stairway should be placed an openable window or similar providing an area of 1 m2.
For a protected shaft containing a lift or multiples thereof, a permanent opening of 0.1 m2 per lift is required.
The openings are to ensure that any smoke finding its way into the protected lobby will rise and be drawn out of the window by the cooler air. Some circumstances may warrant the use of mechanical smoke extraction, but this should be a decision taken by the design team and fire engineers working on the build.
Subdivision of roof and ceiling voids
Fire and its by-products, smoke and toxic gases, can spread easily through roof voids if this is not prevented. For this reason, roof and ceiling voids must be sub-divided with fire-resisting construction to at least 30 minutes fire resistance. The maximum undivided area should not exceed 400 m2.
Openings between the sub-divided void areas should be limited to doors which have 30 minutes fire resistance and pipes that are suitably fire-stopped to an equivalent level and made of appropriate materials.
In Part 117 of LWF’s blog series, LWF will consider elements of structure and fire resistance. 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 since 1986 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.