TG20:2013 Compliance Sheet

I have been given a compliance sheet for a relatively straightforward scaffold and have done a couple of checks on the result. One thing is puzzling me and I wonder if anyone can check this.

If I use the data for the weight of lifts from the tables and calculate the standard loading, I get a significantly different loading (much lower) than the quoted 'Foundation design leg load' on the sheet. I can't find anything that defines whether this is a characteristic load or an actual (factored) design loading but the difference between my figure & the compliance sheet one doesn't seem to be related by a partial safety factor within the range that I would expect.

I have got the reason for the difference - it is due to longitudinal loadings being transferred through the scaffold, resulting in additional vertical loads in some standards (& presumably lower vertical loads in other standards.

I am still not certain about the definition of 'design load'. It seems that it is probably an SLS design load with partial load factors of 1.0 but I am trying to clarify that now.

Have they considered that the full wind won't be acting at the same time as live loading on an access scaffold? i.e. it should be working wind only + any horizontal component of the live load. If not the calculated leg loads may be higher than those which will occur in practice (unless it's a loading platform or similar which could have full wind and live load at the same time).

Still haven't really had time to look at this to be honest - but could it be the tables are SW only while the compliance sheet is adding in the LL?

Either way I believe these loads are still SLS unless they have fundamenally changed the way they do things...

The problem with using limit state design is that you can't just believe or assume what state the loads are quoted in otherwise you will make a big mistake sooner or later. You have to know and it really should be defined in the compliance sheets.

The tables all include live loads if you pick the lines with anything other than zero live load when selecting the weight of boarded lifts.