Cement was then poured in to fill the gap between the two walls and create a kind of 'crown' on the top.

If I venture to wonder whether the whole thing might be a little over-engineered, Philius tells me that water is very heavy and very strong and its container needs to be man enough for the job.

Fiberglass shells can only be used for small pools, not 'hotel sized' ones like mine, it seems.