We’re going to tell you about a particular piece of bad practice that isn’t that uncommon.  We’ve been discussing it with Tony Thorpe from Campbell Reith who often vets structures at Olympia, ExCel and Earls Court amongst others and who has seen (and stopped) reputable companies committing this H&S malpractice.

When your event isn’t big enough to warrant a specialist engineer such as Tony on site watching your hire supplier’s every move, it pays to know what to look out for.  After all, it might be a small event but the consequences of poor health and safety practice are just as big.

So what is this sin?

Hanging decks on their bolts rather than properly supporting them.  We start easily enough. You (or more likely others you’ve contracted in) are laying deck together to create a platform of some kind. Simple?  Not quite.  Deck were conceived to have a supporting leg in each corner.  Indeed, that all-important load rating assumes that there is a leg or some form of support in each corner.

However, some people cut corners (pun intended).  Perhaps they’ve run out of legs.   Most often, adjacent legs obstruct two common scenarios.  To level a a stage on uneven ground you need a screwjack.  You can’t use one on adjacent legs.   To brace the stage you need fixed or swivel clips. You can’t attach these to adjacent legs.

At this point some people turn to bolts.  But bolts alone are not a safe solution – as a structural engineer would say, those people are relying on the strength of the bolt in shear and it’s not designed to be used like that.

Over the years we’ve developed various solutions to this problem. Our latest, and favourite so far, is a re-design to our flanged leg system.that was developed in the Steeldeck LA office and which we’ve tweaked ever so slightly.

Why is this important?

Well, quite often you don’t know for sure what weights will be going on your deck. Sure, the stage may just be for a band and how much can four people and a couple of guitars weigh? Yet it’s easy to forget about the activities that don’t form part of your event; for example, what about access equipment?  Someone might need to a drive a genie lift across the stage to hang or focus some lights.

There is a minimum requirement for a stage loading that is laid out in the Institute Of Structural Engineer’s Guide to Temporary Demountable Structures and that is 5kN/m2.  That is 0.5 tons per square metre and if that’s for public use then once you’ve added a safety factor of 1.5 your minimum requirement is 7.5kN/m2 or 0.75 tons per square metre. In summary, properly supported Steeldeck platforms are never less than 7.5kN/m2, but hanging deck on bolts is well below that , so like many malpractices, this one has a serious health & safety consequence.