Spec Finish

Technical www.thefis.org 9 Sometimes the installation can impact site performance, especially with absorbers fixed directly to a wall. This is because the gap, or lack of a gap, behind an absorber will affect the absorption of sound energy, so it’s important to understand what and how the product was tested and under what conditions, as the Class A absorber may be reliant on a large gap behind the absorber to perform. Fire resistance Fire performance is a different subject entirely. Reaction to fire is the measurement of a material’s contribution to the development and spread of fire, generation of smoke and the production of flaming droplets. Reaction to fire is classified under BS EN 13501-1. Products are tested using a number of standards dependent on their predicted performance. Fire resistance is shown in the test report inminutes, 30 (30minutes), 60 (60 minutes) etc. This refers to the ability of the whole construction to satisfy the European resistance to fire rating (REI) – loadbearing capacity, integrity and insulation. It’s crucial that performance claims are checked ensuring that the ceiling has been tested under the type of structure the specification is beingwritten for, and if the structure/floor has been tested under load. For example, an exposed grid ceiling is unlikely to have evidence of conformity to provide compartmentation, and as the tiles are removable, it leaves the possibility of a breach in the compartment, so ametal furring (MF) ceiling systemwith appropriate test evidence would bemore appropriate. This is explained in more detail in the guide. Fixings There are 13 materials used to create the tiles, panels and fabrics in ceilings and absorbers and a range of systems using the materials to offer designers a palette of visual options as well as performance. Some systems are installed externally, or in huge spaces like airport concourses, or to help with acoustics in spaces like the Royal Albert Hall. No matter what materials are used, the installation quality tolerance method and, importantly, anchors should be thought through and described in the specification. Starting with the anchor, conceivably a key element in the detail, it should not be left to a general ‘suitable’ description, as the correct top fixing method is critical and should be noted on the relevant drawings (BS EN 13964 A.5.7). Top fixings should be specified using this approach: 1. identify the application parameters; 2. check that the structure can take the load of the ceiling and any other plant; 3. check the need for redundancy, i.e., what happens if a fixing or hanger fails? 4. check the environmental conditions; is it humid or subject to wind loading? 5. specify an anchor with a European Technical Approval (ETA); and 6. if in doubt, carry out a preliminary test. The FIS best practice guide to selection and installation of top fixings for suspended ceilings provides more information and help at www.thefis.org/membership-hub/ publications/best-practice-guides/top- fixings-and-suspended-ceilings/ Installation It should be specified that the installation is carried out by competent professionals trained by the manufacturer in the installation of their products, especially where performance is key to compliance, and that the installation should be carried out in accordance with the manufacturer’s installation details and the FIS best practice guide to installing ceilings at www.thefis.org/membership-hub/ publications/best-practice-guides/ installation-of-suspended-ceilings/ It is important to remember that the person specifying the ceiling is responsible for its safe installation, that meets the requirements of the Building regulations (AD B, AD E) and that any maintenance can be carried out safely. Neil Miller concluded: “There has never been a time in construction where the specification has been more important, so this first specification guide from FIS sets out our desire to help everyone involved in the specification of products and systems, and our commitment to raise the safety of residents, occupiers and those who use the built environment”. The specifiers guide for ceilings and absorbers can be downloaded at www.thefis.org/membership-hub/ publications/specifiers-guides/ ceilingsandacousticabsorbers/ If yo u have any queries, email joecilia@thefis.org Fire ‘resistance’ is a system’s ability to resist the passage of fire and excessive heat transfer from one area to another B L s3, d0 L There may or may not be a subscript next to the letter A Subscript ‘?’ means the product has been classified for use as flooring. A subscript ‘L’ means the product has been classified for use as a linear pipe thermal insulation product. The absence of a subscript means the product is for use on walls or ceilings. s3 There is a smoke classification of s1, s2 or s3. s1 represents the highest level of performance. s3 represents the lowest level of performance. B The main part of a classification is its letter: A1, A2, B, C, D, E or F. A1 represents the highest level of performance. F represents the lowest level of ‘No performance determined’. d0 There is a classification for flaming droplets and particles during the tests of d0 to d2. d0 represents the highest level of performance. d2 represents the lowest level of performance. This first specification guide from FIS sets out our desire to help everyone involved in the specification of products and systems, and our commitment to raise the safety of residents, occupiers and those who use the built environment.