Visual courtesy of C2 Builder
ohr notes 8
Minimum dimensions for fire resistance of private residences constructed in reinforced concrete
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In Malaysia, like most countries, it is a statutory requirement that in the event of a fire, a building has to be able to maintain its structural integrity[i] for a given minimum period. This duration is termed the minimum period of fire resistance[ii].
Extract from the Ninth Schedule of the UBBL
Minimum period of fire resistance
This has to be determined in accordance with the Ninth Schedule of the Uniform Building By-Laws (UBBL) and is dependent on the type of use and height of the building structure.
For private residences: The above ground structure needs to have a minimum resistance period of 30 minutes for three storeys and below, and 60 minutes for above. Basements require 60 minutes for four storeys and below, and 90 minutes for above.
Minimum dimensions
As it is a statutory requirement for buildings in Malaysia to be designed in accordance with the UBBL, the minimum dimensions given in the Ninth Schedule of the UBBL must be met.
Although it is statutorily sufficient to meet the minimum dimensions given in the UBBL, where the code of practice adopted for the design of the structure gives a larger value, it may be best practice to adopt the larger value as codes of practice are reviewed and updated more frequently than the UBBL. This is something to be discussed and agreed with the client.
The minimum dimensions needed in accordance with the UBBL, British Standard[iii] and Eurocode[iii] are as given below. The dimensions of a structural element will be the largest of what is needed for fire resistance and other design considerations (collapse under permanent loads, deflection etc).
The minimum dimensions needed in accordance with the UBBL, British Standard[iii] and Eurocode[iii]
Reference
1. Uniform Building By-Laws 1984, Amendment 2021.
2. Figure 3.2, BS8110-1-1 1997.
3. BS EN 1992-1-2 2004.#
[i] The UBBL gives this technical definition for fire resistance period: The period for which an element will meet the requirements in respect of transmission of heat or resistance to collapse with passage of flame when tested in accordance with BS 476.
[ii] Structural integrity in terms of fire resistance is the ability of the structure or structural element to provide an appropriate degree of resistance to flame penetration, heat transmission and collapse.
[iii] The minimum dimensions detailed are from part one of the British Standard and Eurocode. However, part two of the respective codes can be used for more detailed assessments that may result in more economical solutions.
Rev 00 l Februrary 2023 l © ohr 2023
Disclaimer
ohr notes are designed and intended for built environment stakeholders who are not structural engineers, as general information in summary form on engineering topics, current at the time of publication, for general information purposes only. The material may not be applicable in all situations. The contents do not constitute professional advice, are not intended to be a substitute for professional advice and should not be relied upon as such. You should seek professional advice in relation to any particular matters you or your project may have.