Thursday, 18 September 2008

The Use of Aluminium Beams in Scaffolding

Hello everyone,

Firstly I would like to apologise for our lack of posts recently... we've had a very busy summer (if you can call it summer with the weather we've had!) and members of our design team have been on holiday so those remaining have been picking up the slack! Anyway, we're back now!

It seems to me that more and more people when erecting scaffolding incorporating aluminium beams are ignoring (or are not aware of) the requirements for bracing the beams set by the manufacturer
. I do not know of a single beam manufacturer that says their beams do not have to have top and bottom chord ties and at least a single row of plan bracing.

Often beams are used in loading bays, often directly under the working platform. That means 9/10 times the transoms on the top chord of the beam are on singles - not load bearing couplers! Sometimes, boards are laid directly onto the beams! (see photo)

This photo is of a scaffold on St.Pancras Station in London that I noticed whilst waiting for a taxi outside Kings Cross. Boards are laid directly onto beams, beams have no chord ties or bracing so 'technically' they are no better than a double scaffold tube. Not to mention the fact that the supporting independent looks dangerously slender and could fold like a pack of cards under any significant loading.

Load bearing couplers must be used to tie the top and bottom chords of aluminium beams in all scaffolding applications otherwise the beam can not be rated to the safe working load published by the manufacturer - more importantly, if the scaffold were to fail and the HSE were involved, the scaffolding erector would not have a leg to stand on!... and possibly others too such as the scaffolding inspector, hire company, main contractor... etc etc.

Aluminium beams are all different and each has their own bracing requirements, however, if you stick to these simple rules you won't go far wrong:

1. Compression chord (usually top chord) ties at 1.0m centres
2. Tension chord (usually bottom chord) ties at 2.0m centres
3 i. Beams up to 450mm depth - single row of plan bracing full length every 5th bay
ii. Beams over 450mm depth - double row of plan bracing full length every 5th bay
4. Lateral brace (dog-leg brace) every 2.0m in alternating directions.

The photo above is not a unique case, there are examples all over the UK of scaffolders misusing beams, there is one on a house extension opposite the school I coach basketball at where a 450 beam has no bracing, transoms on singles on the top boom supports the working platform and the beams must be spanning at least 6.0m!

The question I have for you is... what is to be done about it?

Do we report every scaffold we see that is not erected to 5973/TG20 or has beams not fixed correctly?
Do we try to inform the scaffolder or client of their mistakes?
Do we wait for someone to get hurt?

I would love to know your thoughts...

Bye for now.