The LWF Blog

Fire Safety for Healthcare Premises – Compartmentation – Part 37

August 30, 2018 1:17 pm

In LWF’s blog series for healthcare professionals, the aim is to give information on best practice of fire safety in hospitals and other healthcare premises. In part 36 of this series, LWF looked at compartmentation and finished by discussing the standards for glazing in a compartment wall and how it should be marked to indicate suitability. In part 37, the subject of sub-compartment walls is discussed, before moving on to protected shafts.


Just as any openings in full compartment walls should be fire-stopped, openings in sub-compartment walls must be protected to provide a minimum period of fire-resistance of 30 minutes.


Uninsulated fire-resistant glazing may be used in sub-compartment walls if it provides a minimum period of fire resistance of 30 minutes in terms of integrity and if the area of glazing does not exceed 1 m2 in any room. However, if sprinklers are in use, the limit is lifted, provided that the glazing is not of the type described as ‘modified toughened’.


Where glazed screens have 30 minutes minimum fire-resistance for both integrity and insulation, there are no limits as to the amount possible within a room.


Protected Shafts


In part 36 of this series, the requirements for openings in compartment walls were laid out. In the case of protected shafts, any openings which do not comply with those requirements must be enclosed in a protected shaft which has the same period of fire resistance in terms of integrity, insulation and, where appropriate, load-bearing capacity, as the compartment floor.


A precis of the requirements for openings in compartment walls can be found in HTM 05-02 paragraph 5.17.


The protected shaft must form a complete barrier to fire between the two compartments that the shaft connects and should be constructed from materials of limited combustibility. In cases where services should pass through the structure, they must be fire-stopped to maintain the fire-resistance of the enclosing structure. Such services might be pipes, cables or ducts.


Internal glazing (ie. Glazing placed in an internal wall as opposed to an outside wall) in a protected shaft must have the same period of fire-resistance in terms of integrity and insulation as the protected shaft itself.


Where roof lights are to be placed over protected shafts used for stairways, they should provide a Class 1 surface spread of flame on both upper and lower surfaces.


Protected shafts should not include any accommodation and may only be used to protect stairways, lifts, escalators, chutes, ducts and pipework. Pipes which are used to transport oil or ventilation may not be situated in the same shaft as a stairway or lift, except those pipes to provide oil to the hydraulics of a lift and any ventilation ductwork for pressurising a stairway.


All protected shafts which incorporate a stairway must be provided with an opening window or vent which provides clear ventilation of 1 m2.


In part 38 of this series, LWF will look at protected lobbies and fire stopping. 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 Peter Gyere on 020 8668 8663.


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.


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