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TG20:13 was issued by the NASC as new guidance that will impact on all tube and fitting scaffold design in the UK. As of June 2014 it is the only guidance that is acceptable to the HSE.

TG20:13 has been issued as the industry technical guidance on the use of the European Standard BS EN12811-1 and applies to all tube and fitting scaffolds from the most basic to the most complex structure.

TG20:13 is based on the previous version TG20:08 and UK British Standard BS 5973:1993 ‘Access and working scaffolds and special scaffold structures in steel’, which was withdrawn by British Standards because it was not compatible with the new European Standard BS EN 12811-1.

Fundamentally, the principles of BS 5973 remain unchanged and there are very few changes in the day-to-day work of a scaffolder. Although the scope of TG20:13 is generally wider than in previous guidance, it is the justification of the design that has altered rather than the scaffold structure itself.

While dealing with many common applications, TG20:13 defines a range of scaffolds, referred to as ‘Basic scaffolds’, for which no further design is required to establish the capability of the scaffold. These scaffolds include: -

  • Independent skeletal tied scaffold
  • Independent tied debris netted scaffold
  • Independent tied sheeted scaffold
  • Putlog scaffold

All other scaffolds now require a design drawing and / or calculations. Typical design scaffolds are:

  • Access scaffolds with more than 2 working lifts
  • Certain birdcage scaffold
  • Cantilever scaffolds
  • Certain loading bays
  • Large span bridges in scaffold
  • Temporary buildings / roofs
  • Scaffolds to radial buildings
  • Load bearing scaffolds
  • Shoring / support scaffolds
  • Storage racking (i.e. truss rack)
  • Untied free standing scaffolds
  • Any scaffold that is slung, hung or trussed out

This list is not exhaustive but offers a general description for types of scaffolds requiring design input.

TG20:13 covers 4 load categories only: -

Class 1 Very Light Duty 0.75 kN/m²
  Class 2 Light Duty 1.5 kN/m²
  Class 3 General Purpose 2.0 kN/m²
  Class 4 Heavy Duty 3.0 kN/m

For more information regarding TG20:13 or BS EN 12811, please contact us using our contact page or go to our Useful Links Page.

TG20 Scaffold Design
TG20 Compliance Sheet
Access Design & Safety Ltd, 1 Parsons Street, Dudley, West Midlands, DY1 1JJ
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