The LWF Blog
Fire Safety for Healthcare Premises – Thermoplastic Materials – Part 31
July 19, 2018 11:57 amIn 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 30, we discussed the potential for internal fire spread and in part 31, we take a look at the use of thermoplastic materials in roof lights and lighting diffusers.
In part 30, the national and European classifications for linings within spaces contained in healthcare buildings were detailed. The exception to this rule is thermoplastic materials used in roof lights and lighting diffusers which may be used even if they do not meet the performance standards given, provided they meet certain requirements.
The requirements are relevant, whether or not the light diffuser fitting is enclosed within the ceiling and so the lighting source appears flush with the ceiling plane, or it is positioned below the ceiling so the fitting is visible within the room.
Those thermoplastic roof lights and lighting diffusers which have a classification of lower surface of TP(a) can be used in all locations except stairways, with no restrictions on the following:
i. The maximum area of each diffuser or roof light
ii. The maximum total area of diffusers or roof lights
iii. The minimum separation between diffusers or roof lights
Thermoplastic roof lights and lighting diffusers having a classification of lower surface of TP(b) and roof lights with a Class 3 rating can be used in any area with the following restrictions:
i. Each diffuser or roof light should have a maximum area of no more than 5m2
ii. The maximum total area of diffusers and roof lights should be no more than 15% of the floor area of the space.
iii. Roof lights should have a minimum distance between of 3m in any direction.
Thermoplastic roof lights with a classification of upper surface TP(b) should not be used at all and no thermoplastic lighting diffuser should be used in a fire-resisting ceiling unless they have been tested satisfactorily as a part of the ceiling assembly providing the appropriate fire protection.
The minimum distance from a relevant boundary of thermoplastic roof lights with a classification of upper surface of TP(a) should be at least 6m.
Diagrams to assist with an understanding of positioning and standards can be found in HTM 05-02 – Fire safety in the design of healthcare premises.
In part 32 of this series, LWF will look at internal fire spread through the structure of a building. In the meantime, if you have any queries about your own facilities or wish to discuss this blog series, please contact Peter Gyere in the first instance on 0208 668 8663.
Lawrence Webster Forrest is a fire engineering consultancy based in Surrey with over 25 years’ experience, which provides a wide range of consultancy services to professionals involved in the design, development and construction and operation of buildings.
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.