In this context, ‘gauging’ is the term used to describe the measuring out of quantities of individual dry materials for a concrete mix. It is a common practice – and a bad one – on many construction projects simply to load a concrete mixer using a shovel, with the result that there is no accurate control in terms of gauging the proportions of materials. For example, one shovelful of damp sharp sand has greater volume than one shovelful of dry cement powder, so mixes batched in this way often contain too little cement. Realistically, the only way that a degree of accuracy can be employed is to use batching by weight or by volume. The same principles apply to measuring out materials for mortar mixes.