TG20 is a guide to good practice for tube & fittings scaffolds produced by the NASC. The latest version of this guidance TG20:21 builds on the previous version TG20:13. There are a number of differences between TG20:13 & TG20:21. Perhaps the biggest change is in the way the new guide is delivered. Previously TG20:13 was outlined in two physical books, the TG20:13 Operational Guide & the TG20:13 Design Guide. These were accompanied by the TG20:13 e-guide software for producing the TG20 compliance sheets, but the software was only licensed for use on one machine. For TG20:21 the Operational Guide, Design Guide & e-Guide software have all been incorporated into a subscription based online portal called the NASC e-Portal. This allows for several devices including computers, tablets & smart phones to access the guide with one subscription.
There are a number of changes within the guide itself & the e-Guide software has also been updated to allow TG20 compliance sheets for a wider range scaffolds. Below is a list of some of the changes that have been made. Although this list is not exhaustive, we have tried to include the most important changes. A full list of the changes are listed within TG20:21 itself.
TG20:21 eGuide Software
As mentioned above, the e-Guide software has been updated to include a wider range of scaffolds. Also, each TG20 compliance sheet produced by the software is now more detailed. The layout of a TG20:21 compliance sheet now spans over two pages with an illustration of the scaffold and the main compliance criteria on the first page, with more detailed compliance criteria on the second page.
Some of the additional TG20 compliant scaffolds that have now been added within software include tied independent scaffolds with up to three inside boards, external birdcages, mobile towers and loading bays without the need to use beams. Loading bays with beams have also been modified to replace the 5 board width with the options for either a 6+2 board width or a 3+4+3 board width. The compliance sheet for birdcage scaffolds has been improved to allow for multiple boarded lifts as well as the option for just the perimeter bays to be boarded.
Below is a list of the key changes that have been made with in the Operational Guide.
The guidance for the maintenance of scaffold boards has been revised in line with TG6:17
The guidance for supplementary and check fittings from TG14:20 has been included.
Additional guidance has been provided for the use of TG20 compliant aluminium lattice beams as well as practical guidance for the storage and transportation of beams.
Guidance on ladders has been updated following the introduction of BS EN 131
Guidance for when sole boards should be used in addition to plastic plates has been clarified.
Scaffold load classes and permissible platform widths have been updated to permit three inside boards
Guidance for board bearing transoms has been extended to include three inside boards
Guidance for structural transoms has been revised to state they may be connected to standards or ledgers.
Guidance for inside board brackets has been amended to permit up to three inside boards.
For tie assemblies, guidance has been provided for the use of K bracing where a tie tube is more than 300mm from a standard.
For ladder towers the maximum recommended vertical distance between landings has been reduced from 9.0m to 6.0m in line with SG25:20
The guidance for the safe use of gin wheels has been revised in line with SG9:21
The guidance on Loading Bays has been revised to include the additional width options within the TG20:21 compliance sheets
Guidance has been provided for external birdcages in addition to internal birdcages as per TG20:13
Guidance has been provided for TG20:21 compliant mobile towers
The Risk Assessment & Method Statement section has been updated in line with SG7:19