The assessment of the light steel frame system will be based on the information provided in a system manual submitted by the manufacturer. The system manual should be in English and contain the information listed below relevant to the elements they wish to be assessed.
The structural components of the system must meet serviceability limit state (SLS), the ultimate limit state (ULS) and durability criteria, including disproportionate collapse where applicable. Engineering judgement will be used in the assessment of the system manual.
Information to be contained in the system manual
Description of system:
Key features
Application: The use(s) to which the system can be put, e.g. max number of storeys, type of cladding
Durability:
Evidence that design life is at least 60 years; Grade of steel; Corrosion protection; Supplementary protection
Strength and stability:
Structural design philosophy; Codes of Practice referenced and test reports; Grade of steel (traceability); Section properties; Loading; Ultimate Limit State; Serviceability Limit State; Resistance to overturning; Stability / Racking resistance; Holding down; Connections
Structural integrity; Positions and sizes of holes through members
Claddings:
Which claddings are acceptable; Provision of cavity; Type of wall ties
Behaviour in relation to fire:
Which internal linings are necessary; Fire-stops and cavity barriers
Condensation risk;
Type, thickness and location of insulation material
Sound insulation:
Does specification comply with Building Regulations / Robust details?
Balconies, terraces and parapets:
Any specific design considerations
Other:
Other information of relevance to the designer and steel frame certifier
Note: The SCI may ask for additional information.
The assessment is usually in two parts; an initial review, followed by the full assessment procedure.
In the initial review the SCI will reconsider the submitted information and provide a report giving:
• An assessment of the completeness of the information
• An indication of any omissions that would have to be rectified for the assessment to progress
• A quotation for the full assessment procedure.
The full assessment will follow these steps.
1. Review of System Manual
The system manual will be reviewed to ensure that:
• The claimed range of uses is covered by the manual
• The structural design philosophy is valid and has been followed and any project specific requirements such as the need for supplementary calculations are clearly described
• The instructions regarding the need for, and usage of, the various components in the system are clearly described
• The applicability to different cladding systems and constraints on the usages are clearly described
• Any special fixing requirements or additional components not part of the suppliers system are explained, e.g. timber wall plates, timber roof trusses, brick ties etc.
• The appropriate load factors and limiting serviceability criteria are clearly described
• The limitations and scope of the system are clearly described.
The Steel Construction Institute will have the right to consider any relevant information from any source in determining an application.
2. Review test regime
Where the system relies on testing, the reports on the test procedures will be reviewed against the following criteria:
• The appropriateness and independence of those carrying out or supervising the test work
• The conformity of the test conditions in representing the intended conditions of use
• The completeness of the test programme to cover the relevant claimed range of use in terms of (Spans range, Section range, Support conditions, Cladding and fixings, Load conditions, Wall heights, Bracing configurations, Holding down)
• The accuracy of the measurements of loads, deflections, material properties and section properties
• Calibration records of equipment
3. Review of derivation of design data from test results
The treatment of the test results will be reviewed to ensure that:
• The results have not been extrapolated to extend the design data beyond the limits of the test programme
• The design expression(s) derived take all significant factors into account
• An appropriate statistical method has been used in deriving the design data from the test results. Compliance with the rules given in either BS 5950-5 or Eurocode 3-1.3 will be deemed to satisfy this requirement.
• Where calculations have been used in addition to, or in place of, test results, these are appropriate and accurate.
• All significant parts of the system have been evaluated.
4. System Assessment report
The SCI will produce a report on the results of its reviews of the information provided. Any omissions and lack of compliance will be set out for the manufacturer to address.
When the SCI is satisfied that the information provided demonstrates the validity of the system manual, the assessment certificate will be issued, covering the systems which have passed the assessment procedure, together with any conditions on usage.
In the event that the system manual does not satisfy the assessment requirements, the manufacturer will be required to submit a suitably amended manual for the assessment to proceed.
The assessment shall be valid for a period of not more than 3 years after which time the manufacturer shall have the system re-assessed or the validity of the system will lapse.
During the 3 year period, any proposed revisions to the use of the system shall be notified to the SCI who shall determine the effect on the assessment. The SCI (and NHBC) has the right, after suitable consultation, to suspend or withdraw assessment in the light of new information.
The limitations of the assessment must be clear in all publicity material and brochures.
Indemnity
The SCI shall be fully indemnified by the system supplier against all costs, charges, expenses, damages and liabilities howsoever incurred by the SCI in relation to the Light Steel Framing System insofar as the same is attributable [whether directly or indirectly] to any act or omission of the Supplier or its servants, agents or employees.
The validity of the assessment shall be dependent on indemnity being in place.
The SCI makes no warranties or representations about any assessed systems or their suppliers save those set out in the assessment certificate.
Administrative issues
The SCI report and information supplied by the supplier will be stored electronically for record purposes. Hard copy of the supplier information and SCI report will also be retained.