Technical guidance to the Building Regulations within the countries which make up the United Kingdom (UK) permits services of limited diameter, including plastic waste pipes, to penetrate fire resistant wall or floor constructions without protection other than fire-stopping the annular space around the penetration. Within the UK, Scotland is singular in additionally limiting the number of pipes and the spacing between pipes within a grouping in close proximity. When this guidance was first introduced in Scotland the permissible use of combustible forms of constructions was less common than it is today. Additionally in the intervening period engineered timber products such as timber I-joists, which may comprise thinner section sizes than traditionally sawn joists or studs, have been introduced to the UK construction market. If it is the case that charring of structural members, which comprise timber I-joists, takes place within a construction cavity as a consequence of unprotected service penetrations, then premature local failure could result. Such failure would undermine the fire resistance of the construction, potentially endangering building occupants and also pose a danger to fire-fighters.
Three reduced scale fire resistance tests were carried out upon combustible floor constructions, containing timber I-joists, which were penetrated by unprotected waste pipes. All of the pipe arrangements would be acceptable in terms of building regulation guidance in Northern Ireland, England and Wales; whilst only one of the arrangements would adhere to the Scottish guidance. In all instances temperatures recorded within the construction cavities were indicative of charring of timber members adjacent to the service penetrations.
|Title of host publication||Proceedings of the 1st International Conference on Structural Safety under Fire & Blast CONFAB 2015|
|Editors||A. Usmani, Y. Lu, P. Das|
|Number of pages||9|
|Publication status||Published - Sep 2015|
- building regulations
- fire safety
- fire resistance