Hi Susan

I don't think there is any specific recommendation as to the answer to your question!

But if you stand away from the scaffold, e.g. on the other side of a road, you should be able to see whether all the standards are vertical and all the ledgers are horizontal - if they look wrong, they are. Your eyesight can tell without any equipment whether things are within tolerance as regards verticality and horizontality.

If you take the first of the common systems to be mass marketed in the UK, i.e. Kwikstage, then each connection is dependent on its "banana" and "wedge". If the banana doesn't sit properly in the wedge, then the tube is unlikely to look right from a distance. SImilar principles apply to Cuplok or the more sophisticated systems that subsequently came on the market.

Rather than concentrate on this aspect, I would give closer attention to any components that are tube and fitting, e.g. to fill in gaps where a system scaffold is erected alongside a structure which is not completely straight, e.g. at oriel windows on a building + whether the footings, ties and bracing are in accordance with the manufacturer's instructions.

....and since system scaffolds are easier to erect (and thence sometimes put up by people who have not had full scaffolder training), I would be putting close attention to checking that the recommended proportion of ties have been subject to pull out tests.

If you were talking about tube and fitting scaffolds I would add overhanging boards or the lack of intermediate transoms but this is less of an issue with systems as the boards fit neatly within the system. Always assumes that the system is built with its proprietary units!!

P