ROOFING, CLADDING & INSULATION
PREVENTING THE SPREAD OF ROOF FIRES IN TERRACED AND SEMIDETACHED HOUSING With recent reports raising concerns about inadequate fire barriers in the roofs of some newbuild homes, Stuart Nicholson, Roof Systems Director at Marley, says all social housing providers should review fire stopping specifications. are an unseen, F irebutbarriers very important, product when installing a pitched roof on terraced or semidetached housing. When a roof is compartmentalised, fire stopping is required between the top of the party wall and the roofcovering, acting as a seal to prevent spread of flames and smoke between properties in case of fire. However, there have been some house fires in recent years where the fire has spread across the line of the party wall and caused damage to neighbouring properties. This issue of fire spreading in roof
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voids was addressed in separate reports from the BRE and BBC Watchdog, which raised concerns that some modern homes could have inadequate, incorrectly installed and, in some cases, no fire barriers at all. In fact, investigations found that 650 new homes in one region of the UK had missing, or incorrectly installed, fire barriers. Whilst the research took place in private new builds, it is equally concerning for the social housing sector, which has a large proportion of terraced and semi-detached
homes, multiple occupancy buildings and flats (which also require fire breaks in the roof). Clearly, any home without fire stopping is in breach of the Building Regulations and this is very worrying. However, the fact that, in some cases, fire barriers had been installed but they may not have worked effectively, is just as troubling. Unfortunately, there are a few reasons why a fire barrier could end up being inadequate or incorrectly installed. Fire stopping is often achieved with a flexible mineral fibre quilt or sock, but a potential fire passage still exists at the line of the roofing battens, above the rafters, which can span across the junction between properties. In addition, standard details, such as spandrel panels in
timber frame construction, may be used to satisfy fire separating requirements but don’t provide fire stopping to the underside of the roofcovering. There are fire barrier products available on the market to close this gap but feedback from contractors suggests that these can be bulky and difficult to install in line with the roof tiles, especially with deep-profiled tiles. It is also difficult to see if the fire protection is in the correct place once the tiles have been laid. This means there is a risk that social housing providers have specified a fire barrier and it is present, but it may not be installed correctly, or might not be sufficient to fully seal the gap.
