Spec Finish

Technical www.thefis.org 13 1. Critical building information; and 2. Risks and how to avoid them. In total, there are 48 questions and 10 top tips on writing a smart specification to ensure that a safe, compliant and complete specification is written. All of which is critical to ensure that the specification is not open to misinterpretation, and that any alternatives can be assessed and checked as being equivalent, before approving them. Critical building information is best supplied in response to the initial request for information (RFI) from themanufacturer; where details of the building’s, location, height, framework, deflection, movement, fire performance, elevation, insulation, loads, window sizes, external features such as balconies and environmental conditions, (humidity, salt,) are provided. Additional information will also be required to understand any load fromwind, external façades, doors, windows and linings etc. before the design work can begin. All of this takes time which should be factored in during the programme planning. Remember that it is the responsibility of everyone involved in this process to ensure that the building can be designed and constructed safely and that it will meet the requirements of the Building Safety Act and the Building Regulations. Through the wall systems Infill SFS is sometimes sold as a system that includes the internal lining boards, insulation, steel framing and external sheathing boards. These ‘through the wall’ systems can provide evidence of fire and acoustic performance, the external insulation, cavity barriers, cavity trays and external claddingmay be from separate supply routes so early collaboration and coordination will be key to ensure compliance. One of several other considerations is condensation, identifying the risk where cold spots can occur, and specifying mitigating measures such as the installation of vapour barriers, as well as understanding the risk where SFS is installed below ground level, for example, to form a basement, where water ingress is a potential risk. The interface of the SFS with the structure and the internal layout should be carefully considered to address points where the SFS framework is directly installed to steel framework protected with reactive coating (intumescent paint), which may be required to be boxed in before the SFS can be installed to maintain the acoustic and air tightness requirements. Similarly, the junction with compartment walls and the SFS where the internal lining should be installed either side of the compartment wall to maintain acoustic and fire performance. The guide includes these 10 top tips to writing a smart specification: 1. Talk to the manufacturer. 2. Performance is king. 3. Consider the interface with other elements and junctions. 4. Understand the requirements. 5. Understand the budget. 6. Understand the programme and site conditions. 7. Understand the vision and client aspiration. 8. Ensure the performance and workmanship requirements and standards are clearly included. 9. Understand the implications of maintenance, and 10. Understand the environmental implications and what will happen at end of life. The specification can take two forms: • A very prescriptive specification at tender stage will ensure the client has a high degree of certainty about what will be delivered; or • A performance specification gives suppliers more discretion – for example, to suggest innovative solutions and/or to act as a design brief for specialist subcontractors. Either one can only be produced after the design is developed using the information from the RFI. Final spec Specification documents should be produced in tandem with the design work, with ever greater level of detail added as the design progresses. At tender stage, the specification serves as an essential reference guide for contractors looking to price a job. Leaving specifications until the last minute – when production information is being prepared – is not to be advised. The final specification should clearly describe: • manufacturer; • reference; • framing; • bracing; • brackets; • anchors; • boards internal; • boards external; • fixings; • vapour barrier; • insulation; • cladding; and • workmanship. The guide also includes a checklist looking at structural design, interfaces, installation drawings and the infill panels, as well as detailed information from the engineers on the specification fixing centres and edge distances of anchors, and the specification fixing centres and edge distances of board fixings (fasteners). The specification should also include expected levels of tolerances andworkmanship referencing the BS 8000 series of standards. Top 10 risks to consider when writing a spec 1. Incorrect specification of light gauge steel framing. 2. Incorrect selection of anchors and fixings. 3. Incorrect installation (e.g., insufficient deflection head). 4. Additional load applied. 5. Insufficient number of anchors or fixings. 6. Failure to follow manufacturers’ guidance/instructions. 7. Modification by other trades. 8. Insufficient supervision/training. 9. Substitution of specified component. 10. Incorrect interface with other building elements. The best advice FIS can give is to engage with the experts early, (specialist contractors and manufacturers), and provide all the information requested to ensure a compliant specification. Colin Kennedy said: “The construction industry is rightly under the microscope to ensure that the lessons from the terrible tragedy at the Grenfell Tower are learned and that this starts with ensuring that the specification is clear, complaint and written and subsequently installed by those who can demonstrate they have the skills, knowledge, experience and behaviour (SKEB) to be considered competent.” FIS vets all members when they apply for membership and then every three years. A list of members offering infill SFS can be found here: www.thefis.org/member-direct ory/?businesstype=contractors-specialist FIND OUTMORE Download the FIS Specifiers Guide for Infill SFS at www.thefis.org/ membership-hub/publications/ specifiers-guides/light-guage-external- wall-systems/ i It is the responsibility of everyone involved in the specification process to ensure that the building can be designed and constructed safely and that it will meet the requirements of the Building Safety Act and the Building Regulations.