New standards for UK scaffolding industry
By Maria Hadlow12 July 2010
By the end of the year the UK scaffolding industry should be fully conforming to the European Standard BS EN12811-1:2003 rather than the withdrawn British Standard BS 5973:1993.
The HSE (Health and Safety Executive) has advised the UK scaffolding industry that time is now running out for the continued use of BS5973: Philip White, Chief Inspector of Construction said, "As from 1st January 2011 the Health and Safety Executive will no longer acknowledge BS5973:1993 as a recognised standard for the design of tube and fitting scaffolding structures."
However, BS EN12811-1 is a performance document and does not give detailed advice on safe systems of work for erecting, altering or dismantling scaffolds when erected using tubes and fittings. To overcome this, the NASC (National Access and Scaffolding Confederation) has produced TG20:08 - Technical Guidance on the use of BS EN12811-1, as a guide to good practice for scaffolding with tubes and fittings.
BSI (British Standards Institution) withdrew BS5973:1993 because of the conflict of information within the two standards. The principal differences between BS EN12811-1 and BS 5973 are:
- The European standard requires all scaffolds to be designed
- There are six service Load Classes, some with partial area loads
- There are seven width classes and two headroom classes
- A requirement for a minimum unimpeded area along the full length of the working platform
- BS5973 gives no differentiation between the loading on main platform and the inside boards
- The definition of an in-service condition and an out-of-service condition
- A reduction in the number of working platforms in use for light duty, general purpose and heavy duty scaffolds. When in use a scaffold is considered to have one platform with 100% of the service load and one adjacent platform (above or below) with 50% of the service load
- In the absence of wind, a scaffold shall have a notional horizontal load, on every bay, applied separately parallel and perpendicular to the bay
- Wind loads on scaffolds shall conform to the national standard BS 6399/EN1991
- Reappraisal of effective lengths for the purpose of estimating the safe loads on standards
- The structural design according to Limit State theory
The new standard is said to offer a number of benefits which include:
- It covers a wider scope than BS5973
- It covers the whole of the UK (BS 5973 was not valid in Scotland)
- It includes scaffold designs that comply with BS EN12811-1 and the requirements of the WAHR 2005 - Schedule 3 - Part 2.
- Retention of ledger bracing every other bay (as agreed with the HSE)
- Differentiation between Unclad, Debris netted and Sheeted scaffolds
- The maximum height for netted and sheeted scaffolds is well above those in BS5973
- TG20 includes a wider and more varied arrangement of tie patterns to achieve maximum heights based on a 4m x 4m grid
- A return to light duty loading on inside boards
- TG20 covers standard solutions for basic independent and putlog scaffolds.