- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 24 Jul 2018
|A construction, other than a smoke curtain, provided to close a concealed space against penetration of smoke or flame, or provided to restrict the movement of smoke or flame within such a space.|
Where a concealed space is:
|A space enclosed by elements of a building (including a suspended ceiling) or contained within an element, but not a room, cupboard, circulation space, protected shaft or space within a flue, chute, duct, pipe or conduit.|
As most buildings contain a multitude of concealed cavities and voids within walls, floors, ceilings and roofs, effective cavity barriers are essential to restrict the spread of smoke or flames. If there is a fire, the intumescent material which makes up the barrier will expand, sealing off the gaps.
Cavity barriers are typically pieces of fire-stopping material which are fitted within building cavities - horizontally at each floor, and vertically at each party wall. This assists with fire compartmentation.
The location of each cavity will determine the appropriate maximum distance between the barriers, as well as the class of surface which is exposed within the cavity. The performance of cavity barriers much be maintained throughout the lifecycle of a building, with consideration given to any building movement due to subsidence, shrinkage, and so on.
Cavity barriers must be fitted tightly to rigid construction, or suitably fire-stopped at a junction between itself and construction to which it cannot be fitted so tightly (e.g. slates, tiles, sheeting, etc.). The likelihood of the fixings failing in the event of a fire should be carefully considered. Services that may run through a barrier should be fire-stopped using appropriate materials.
 Find out more
 Related articles on Designing Buildings Wiki.
Featured articles and news
The world heritage list has evolved to embrace built, cultural and natural heritage.
The Ocean Cleanup project
The various types of bond and when they are used.
It's vital the industry responds to proposals for reform of the safety regulatory system.
RSHP's Merano wins RIBA accolade.
How to differentiate between partial possession and early use.
Ofwat proposes £12 billion additional investment and £50 bill reductions.
Avoiding 'winner's curse' and other useful info.
Developing test methods for video flame/smoke detectors
Waiting for a new deal ...but will funding materialise?