Spec Finish

Technical Specifying a ceiling is not always done by an architect, it might be done as part of a contractor’s design portion, as part of a design and build project, or even as part of offering alternatives. Whichever way, it’s crucial to get it right says FIS Technical Director, Joe Cilia , as the person producing the specification carries the responsibility that the products can be safely installed while meeting the requirements of the building regulations. SPECIFYING CEILINGS 8 www.thefis.org O N the face of it specifying ceilings seems simple enough”, said Neil Miller, Chair of the FIS Ceilings and Absorbers Group, “consider the look, the performance and cost and there it is; if only it were that simple there would not be cases where fire compartmentation fails, partial and full collapses occur, or ceilings fail to perform because the potential wasn’t apparent during the specification process”. In BS EN 13964 Suspended ceilings — Requirements and test methods, a ceiling is defined as: a construction covering the underside of a floor or roof, providing the overhead surface. The Standard defines the tests and tolerance of ceilings, in fact, it is now a UK designated standard requiring systems to be UKCA marked when put on the market in the UK (UKNI mark for Northern Ireland and CE marked when put on the market in the EU) and is a good starting point when understanding the types of ceilings and the performance tests required before they can be put on the market. Function of a ceiling A ceiling’s function could be to conceal services, lower a slab height, help to control acoustics in a space or in adjacent spaces, reduce rain noise, protect a building element in case of a fire, provide compartmentation, reflect light and contribute to a space where air movement is managed. At the same time, it has to function in a space which may have high humidity such as a leisure facility, be able to resist impact from balls as in a sports hall, be cleanable in a food production space, be completely visually flush in a house, allow access but not provide ligature points, or it may even have to allow an exposed soffit and the services to be seen but still absorb sound energy. The permutations are frankly endless and each project should be specified on its performance, its function, its aesthetics, its location and finally, its cost. Remember also that the way it will be supported and fixed to the structure is equally important, yet often described as simply ‘using suitable fixings’! FIS guide for specifying ceilings To help this process, a new guide for specifying ceilings and absorbers has been written by an FIS working group made up of expert specification writers with help from NBS, and is available now to FIS members and specifiers at www.thefis.org/ membership-hub/publications/specifiers- guides/ceilingsandacousticabsorbers/ Neil Miller said: “This guide pulls together decades of experience, from specification managers who almost instinctively know the FAQs on all aspects of ceiling specification such as performance, material characteristics, sustainability and environmental, conformity marking, installation, maintenance and end of life. There are some 36 parameters to consider to ensure a safe, compliant and complete specification can be written.” The guide firstly addresses what a good specification looks like and how it should be structured, it even includes 10 top tips to producing a specification. It then breaks down the key performance issues around fire and acoustics and the other issues of volatile organic compounds, light reflectance, impact resistance, air permeability, wind loading, sustainability and conformity marking. The types of ceilings are described as continuous (wall to wall) or discontinuous types (often referred to as rafts or islands) and has a section devoted to installation, and why ceilings fail or experience partial or total collapses. It’s worth remembering that a well written specification ensures the installationmeets the client’s requirements, and it alsomeans the specifier’s requirements are less open to interpretation, prices at tender stage aremore accurate and performance needs are clear. Ceiling performance testing The actual performance of a ceiling or absorbersmay only come to light during an onsite acoustic test to provide evidence that the reverberation time (in a school for example) meets the requirement laid down in theBuilding Bulletin (BB) for schools or theHealthTechnical Memorandum (HTM) in hospitals. ‘